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SMITHSONIAN INSTITUTION LIBRARIES

PRINCIPLES

GEOLOGY,

BEING

AN ATTEMPT TO EXPLAIN THE FORMER CHANGES
OF THE EARTH'S SURFACE,

BY BEFERENCE TO CAUSES NOW IN OPEBATION.

CHARLES LYELL, Esq., F.R.S.

FOR. SEC. TO THE GEOL. SOC, PROF. OF GEOL. TO KING'S COLL., LONDON.

" The inhabitants of the globe, like all the other parts of it, are subject to change. It is
not only the individual that perishes, but whole species."

" A change in the animal kingdom seems to be part of the order of nature, and is visible
in instances to which human power cannot have extended.''

Playfaih, Illustrations of the Huttonian Theory, §413.

VOLUME THE SECOND.
LONDON :

JOHN MURRAY, ALBEMARLE-STREET.

MDCCCXXXir.

LONDON:
Printed by William Clowesi
Stamford.Street.

L.95&K

WILLIAM JOHN BRODERIP, Esq., B. A.

BARRISTER AT LAW,
F.R.S., F. L.S.j ETC.,

VICE PRESIDENT OF THE GEOLOGICAL SOCIETY OF LONDON.

My Dear Friend,

In dedicating this volume to you, I am glad of an
opportunity of acknowledging the kind interest which you
have uniformly taken in the success of my labours, and the
valuable assistance which you have afforded me in several
departments of Natural History.

I am,

My Dear Friend,

Yours, very sincerely,

Charles Lyell,

London, December 8th, 1831.

PREFACE

The author has found it impossible to compress into two
volumes, according to his original plan, the wide range of
subjects which must be discussed, in order fully to explain his
views respecting the causes of geological phenomena. As it
will, therefore, be necessary to extend the " Principles of
Geology" to three volumes, he prefers the publication of the
present part without delay, because it brings to a close one
distinct branch of the inquiry, the study of which will be found
absolutely essential to the understanding of the theories here-
after to be proposed. Considerable progress has already been
made in the remainder of the work, which will shortly be laid
before the public.

London, December 8th, 1831.

CONTENTS.

Vol. II.

PAOE

CHAPTER I.

Changes of the Organic World now in progress — Division of the Subject —
— Examination of the question, Whether Species have a real existence in
Nature ? — Importance of this question in Geology — Sketch of Lamarck's
arguments in favour of the Transmutation of Species, and his conjectures
respecting the Origin of existing Animals and Plants — 'His Theory of the
transformation of the Orang Outang into the Human Species . . I

CHAPTER II.

Recapitulation of the arguments in favour of the theory of transmutation of
species — Their insufficiency — The difficulty of discriminating species mainly
attributable to a defective knowledge of their history — Some mere varieties
possibly more distinct than certain individuals of distinct species — Variability
in a species consistent with a belief that the limits of deviation are fixed — No
facts of transmutation authenticated — Varieties of the Dog — The Dog and
Wolf distinct Species — Mummies of various animals from Egypt identical in
character with living individuals — Seeds and plants from the Egyptian
tombs — Modifications produced in plants by agriculture and gardening , 18

CHAPTER III.

Variability of a species compared to that of an individual — Species which
are susceptible of modification may be altered greatly in a short time, and in
a few generations ; after which they remain stationary — The animals now
subject to man had originally an aptitude to domesticity — Acquired pecu-
liarities which become hereditary have a close connexion with the habits or
instincts of the species in a wild state — Some qualities in certain animals
have been conferred with a view of their relation to man — Wild elephant
domesticated in a few years, but its faculties incapable of further develop-
ment , 36

CHAPTER IV.

Consideration of the question whether species have a real existence in
nature, continued- — Phenomena of hybrids — Hunter's opinions as to mule
animals — Mules not strictly intermediate between the parent species — Hybrid

viii

CONTENTS.

PAGE

plants — Experiments of Kolreuter — The same repeated by Wiegmann —
Vegetable hybrids prolific throughout several generations— Why so rare in a
wild state — Decandolle's opinion respecting hybrid plants — The phenomena
of hybrids confirms the doctrine of the permanent distinctness of species —
Theory of the gradation in the intelligence of animals as indicated by the
facial angle— Discovery of Tieddemami that the brain of the fetus in mam-
malia assumes successively the form of the brain of a fish, reptile, and bird —
Bearing of this discovery on the theory of progressive development and
transmutation — Recapitulation ...... 49

CHAPTER V.

Laws which regulate the geographical distribution of species— Analogy of
climate not attended with identity of species — Botanical geography — Stations
— Habitations — Distinct provinces of indigenous plants — Vegetation of
islands — Marine vegetation — In what manner plants become diffused —
Effects of wind, rivers, marine currents — Agency of animals — Many seeds
pass through the stomachs of animals and birds undigested — Agency of man
in the dispersion of plants, both voluntary and involuntary — Its analogy to
that of the inferior animals . . . . . .66

CHAPTER VI.

Geographical distribution of Animals — Buffon on the specific distinctness
of the quadrupeds of the old and new world — Different regions of indigenous
mammalia — Quadrupeds in islands — Range of the Cetacea — Dissemination
of quadrupeds — Their powers of swimming — Migratory instincts — Drifting
of quadrupeds on ice-floes — On floating islands of drift-timber— Migrations of
Cetacea — Habitations of Birds — Their migrations and facilities of diffusion
— Distribution of Reptiles and their powers of dissemination . . 87

CHAPTER VII.

Geographical distribution and migrations of fish — of testacea — Causes
which limit the extension of many species — Their mode of diffusion — Geo-
graphical range of zoophytes — Their powers of dissemination — Distribution
of insects — Migratory instincts of some species—Certain types characterize
particular countries — Their means of dissemination — Geographical distribu-
tion and diffusion of man — Speculations as to the birth-place of the human
species — Progress of human population — Drifting of canoes to vast dis-
tances — On the involuntary influence of man in extending the range of many
other species . . . . . . . .105

CHAPTER VIII.

Theories respecting the original introduction of species — Proposal of an
hypothesis on this subject — Supposed centres or foci of creation — Why the

CONTENTS.

PAGE

distinct provinces of animals and plants have not become more blended to-
gether — Brocchi's speculations on the loss of species — Stations of plants and
animals— Complication of causes on which they depend — Stations of plants,
how affected by animals — Equilibrium in the number of Species, how pre-
served — Peculiar efficacy of insects in this task — Rapidity with which certain
insects multiply, or decrease in numbers — Effect of omnivorous animals in
preserving the equilibrium of species — Reciprocal influence of aquatic and
terrestrial species on each other . . . . . . 123

CHAPTER IX.

The circumstances which constitute the Stations of Animals are change-
able — Extension of the range of one species alters the condition of others —
Supposed effects which may have followed the first entrance of the Polar
■ Bears into Iceland — The first appearance of a new species in a region causes
the chief disturbance — Changes known to have resulted from the advance of
human population — Whether man increases the productive powers of the
earth— Indigenous Quadrupeds and Birds of Great Britain known to have
been extirpated — Extinction of the Dodo — Rapid propagation of the domestic
Quadrupeds over the American Continent — Power of exterminating species
no prerogative of Man — Concluding Remarks . , • .141

CHAPTER X.

Influence of inorganic causes in changing the habitations of species-
Powers of diffusion indispensable, that each species may maintain its ground
— How changes in the physical geography affect the distribution of species —
Rate of the change of species cannot be uniform, however regular the action
of the inorganic causes — Illustration derived from subsidences by earthquakes
— from the elevation of land by the same— from the formation of new islands
— from the wearing through of an isthmus — Each change in the physical
geography of large regions must occasion the extinction of species — Effects
of a general alteration of climate on the migration of species— Gradual refri-
geration causes species in the northern and southern hemispheres to become
distinct— Elevation of temperature the reverse— Effects in the distribution of
species which must result from vicissitudes in climate inconsistent with the
theory of transmutation „ , 153

CHAPTER XI.

Theory of the successive extinction of species consistent with their limited
geographical distribution—The discordance in the opinions of botanists re-
specting the centres from which plants have been diffused may arise from
changes in physical geography subsequent to the origin of living species
—Whether there are grounds for inferring that the loss from time to
time of certain animals and plants is compensated by the introduction of

CONTENTS.

PAGE

new species ? — Whether any evidence of such new creations could be expected
within the historical era, even if they had been as frequent as cases of extinc-
tion ? — The question whether the existing species have been created in suc-
cession can only be decided by reference to geological monuments . . 1 76'

CHAPTER XII.

Effects produced by the 'powers of vitality on the state of the earth's sur-
face — Modifications in physical geography caused by organic beings on dry
land inferior to those caused in the subaqueous regions — Why the vegetable
soil does not augment in thickness — Organic matter drifted annually to the
sea, and buried in subaqueous strata — Loss of nourishment from this source,
how supplied — The theory, that vegetation is an antagonist power counterba-
lancing the degradation caused by running water, untenable- — That the
igneous causes are the true antagonist powers, and not the action of animal
and vegetable life — Conservative influence of vegetation — Its bearing on the
theory of the formation of valleys, and on the age of the cones of certain
extinct volcanos — Rain diminished by the felling of forests — Distribution of
the American forests dependent on the direction of the predominant winds —
Influence of man in modifying the physical geography of the globe . .185

CHAPTER XIII.

Effects produced by the action of animal and vegetable life on the material
constituents of the earth's crust — Imbedding of organic remains in deposits
on emerged land — Growth of Peat — Peat abundant in cold and humid cli-
mates — Site of many ancient forests in Europe now occupied by Peat —
Recent date of many of these changes — Sources of Bog Iron-ore — Preserva-
tion of animal substances in Peat — Causes of its antiseptic property — Miring
of quadrupeds — Bursting of the Solway Moss — Bones of herbivorous qua-
drupeds found in Peat — Imbedding of animal remains in Caves and Fissures
— Formation of bony breccias — Human bones and pottery intermixed with
the remains of extinct quadrupeds in caves in the South of France — Infer-
ences deducible from such associations • • . 209

CHAPTER XIV.

Imbedding of organic remains in alluvium and the ruins caused by land-
slips — Effects of sudden inundations — Of landslips— Terrestrial animals most
abundantly preserved in alluvium and landslips, where earthquakes pre-
vail — Erroneous theories which may arise from overlooking this circum-
stance — On the remains of works of art included in alluvial deposits — Imbed-
ding of organic bodies and human remains in blown sand — Temple of Ipsam-
bul on the Nile — Dried carcasses of animals buried in the sands of the
African deserts — Towns overwhelmed by sand-floods in England and France

CONTENTS.

PAGE

— Imbedding of organic bodies and works of art in volcanic formations on
the land — Cities and their inhabitants buried by showers of ejected matter
— by lava — In tuffs or mud composed of volcanic sand and ashes . . 228

CHAPTER XV.

Imbedding of organic remains in subaqueous deposits — Division of the sub-
ject — Phenomena relating to terrestrial animals and plants first considered —
Wood sunk to a great depth in the sea instantly impregnated with salt-water
— Experiments of Scoresby — Drift timber carried by the Mackenzie into Slave
Lake and into the sea — Cause of the abundance of drift timber in this
river — Floating trees in the Mississippi — In the Gulf stream — Immense
quantity thrown upon the coast of Iceland, Spitzbergen, and Labrador — Im-
bedding of the remains of insects — of the remains of reptiles — Why the bones
of birds are so rare in subaqueous deposits — Imbedding of terrestrial quadru-
peds — Effects of a flood in the Solway Firth — Wild horses annually drowned
in the savannahs of South America— Skeletons in recent shell marl — Drifting
of mammiferous and other remains by tides and currents , . . 239

CHAPTER XVI.

Imbedding of the remains of man and his works in subaqueous strata — ■
Drifting of bodies to the sea by river-inundations — Destruction of bridges and

houses — Burial of human bodies in the sea — Loss of lives by shipwreck

Circumstances under which human corpses may be preserved under a great
thickness of recent deposits — Number of wrecked vessels — Durable character
of many of their contents — Examples of fossil skeletons of men — Of fossil
canoes, ships, and works of art — Of the chemical changes which certain
metallic instruments have undergone after long submergence — Effects of the
subsidence of land in imbedding cities and forests in subaqueous strata —
Earthquake of dutch in 1819 — Submarine forests — Berkely's arguments for
the recent date of the creation of man — Concluding remarks , . 253

CHAPTER XVII.

Imbedding of aquatic species in subaqueous strata — Inhumation of fresh-
water plants and animals — Shell marl — Fossilized seed-vessels and stems of
Chara — Recent deposits in the American lakes — Fresh-water species drifted
into seas and estuaries — Lewes levels — Alternations of marine and fresh-
water strata, how caused — Imbedding of marine plants and animals —
Cetacea stranded on our shores — Their remains should be more conspicuous
in marine alluvium than the bones of land quadrupeds — Liability of littoral
and estuary testacea to be swept into the deep sea — Effects of a storm in the
Frith of Forth — Burrowing shells secured from the ordinary action of waves
and currents— Living testacea found at considerable depths , , 272

Xll

CONTENTS.

PAGE

CHAPTER XVIII.

Formation of coral reefs — They are composed of shells as well as corals —
Conversion of a submerged reef into an island — Extent and thickness of coral
formations — The Maldiva isles — Growth of coral not rapid — Its geological
importance — Circular and oval forms of coral islands — Shape of their lagoons
— Causes of their peculiar configuration — Openings into the lagoons — Why
the windward side both in islands and submerged reefs is higher than the
leeward — Stratification of coral formations — Extent of some reefs in the
Pacific — That the subsidence by earthquakes in the Pacific exceeds the ele-
vation due to the same cause — Elizabeth, or Henderson's Island — Coral and
shell limestones now in progress, exceed in area any known group of ancient
rocks — The theory that all limestone is of animal origin, considered — The
hypothesis that the quantity of calcareous matter has been and is still on the
increase, controverted , . •* . « 283

ERRATA.

Frontispiece, for Montagnola read Montagnuola.

Page 39, line 2 from the bottom, for excusively read exclusively.

131 — 14 — top — Hypnum — Sphagnum.

147 — 21 — top, dele of.

178 — 8 — top, for even read ever.

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PRINCIPLES OF GEOLOGY.

CHAPTER I.

Changes of the Organic World now in progress — Division of the subject — Exa-
mination of the question, Whether Species have a real existence in Nature ?
— Importance of this question in Geology — Sketch of Lamarck's arguments
in favour of the Transmutation of Species, and his conjectures respecting the
Origin of existing Animals and Plants — His Theory of the transformation
of the Orang Outang into the Human Species.

In our first volume we treated of the changes which have
taken place in the inorganic world within the historical era,
and we must next turn our attention to those now in progress
in the animate creation. In examining this class of pheno-
mena, we shall treat first of the vicissitudes to which species are
subject^ and afterwards consider the influence of the powers of
vitality in modifying the surface of the earth and the material
constituents of its crust.

The first of these divisions will lead us, among other topics,
to inquire, first, whether species have a real and permanent
existence in nature; or whether they are capable, as some
naturalists pretend, of being indefinitely modified in the course
of a long series of generations ? Secondly, whether, if species
have a real existence, the individuals composing them have been
derived originally from many similar stocks, or each from one
only, the descendants of which have spread themselves gradu-
ally from a particular point over the habitable lands and waters?
Thirdly, how far the duration of each species of animal and
plant is limited by its dependance on certain fluctuating and
temporary conditions in the state of the animate and inanimate
Vol. II. B

lamarck's theory of the

[Ch. I.

world ? Fourthly, whether there be proofs of the successive
extermination of species in the ordinary course of nature, and
whether there be any reason for conjecturing that new animals
and plants are created from time to time, to supply their place?

Before we can advance a step in our proposed inquiry, we
must be able to define precisely the meaning which we attach to
the term species. This is even more necessary in geology than
in the ordinary studies . of the naturalist ; for they who deny
that such a thing as a species exists, concede nevertheless that
a botanist or zoologist may reason as if the specific character
were constant, because they confine their observations to a
brief period of time. Just as the geographer, in constructing
his maps from century to century, may proceed as if the
apparent places of the fixed stars l-emained absolutely the
same, and as if no alteration was brought about by the preces-
sion of the equinoxes, so it is said in the organic world, the
stability of a species may be taken as absolute, if we do not
extend our views beyond the narrow period of human history ;
but let a sufficient number of centuries elapse, to allow of
important revolutions in climate, physical geography, and
other circumstances, and the characters^ say they, of the de-
scendants of common parents may deviate indefinitely from
their original type.

Now, if these doctrines be tenable, we are at once presented
with a principle of incessant change in the organic world, and
no degree of dissimilarity in the plants and animals which may
formerly have existed, and are found fossil, would entitle us to
conclude that they may not have been the prototypes and pro-
genitors of the species now living. Accordingly, M. Geoffroy
St. Hilaire has declared his opinion, that there has been
an uninterrupted succession in the animal kingdom effected
by means of generation, from the earliest ages of the world
up to the present day ; and that the ancient animals whose
remains have been preserved in the strata, however different,
may nevertheless have been the ancestors of those now in
being. Although this notion is not generally received, we

Ch. I.]

TRANSMUTATION OF SPECIES.

feel that we are not warranted in assuming the contrary,
without fully explaining the data and reasoning by which we
conceive it may be refuted.

We shall begin by stating as concisely as possible all the
facts and ingenious arguments by which the theory has been
supported, and for this purpose we cannot do better than offer
the reader a rapid sketch of Lamarck's statement of the proofs
which he regards as confirmatory of the doctrine, and which he
has derived partly from the works of his predecessors, and in
part from original investigations.

We shall consider his proofs and inferences in the order in
which they appear to have influenced his mind, and point out
some of the results to which he was led while boldly following
out his principles to their legitimate consequences.

The name of species, observes Lamarck, has been usually
applied to ' every collection of similar individuals, produced
by other individuals like themselves *.' This definition, he
admits, is correct, because every living individual bears a very
close resemblance to those from which it springs. But this
is not all which is usually implied by the term species, for the
majority of naturalists agree with Linnseus in supposing that
all the individuals propagated from one stock have certain
distinguishing characters in common which will never vary,
and which have remained the same since the creation of each
species.

In order to shake this opinion, Lamarck enters upon the
following line of argument. The more we advance in the
knowledge of the different organized bodies which cover the
surface of the globe, the more our embarrassment increases, to
determine what ought to be regarded as a species, and still
more how to limit and distinguish genera. In proportion as
our collections are enriched, we see almost every void filled
up, and all our lines of separation effaced ; we are reduced to
arbitrary determinations, and are sometimes fain to seize upon

# Phil. Zool. tom.i. p. 54.

B 2

lamarck's theory of the

[Ch. I.

the slight differences of mere varieties, in order to form cha-
racters for what we choose to call a species, and sometimes we
are induced to pi'onounce individuals but slightly differing, and
which others regard as true species, to be varieties.

The greater the abundance of natural objects assembled
together, the more do we discover proofs that everything passes
by insensible shades into something else ; that even the more
remarkable differences are evanescent, and that nature has,
for the most part, left us nothing at our disposal for establish-
ing distinctions, save trifling and, in some respects, puerile
particularities.

We find that many genera amongst animals and plants are
of such an extent, in consequence of the number of species
referred to them, that the study and determination of these
last has become almost impracticable. When the species are
arranged in a series, and placed near to each other, with due
regard to their natural affinities, they each differ in so minute
a degree from those next adjoining, that they almost melt into
each other, and are in a manner confounded together. If
we see isolated species, we may presume the absence of some
more closely connected, and which have not yet been dis-
covered. Already are there genera, and even entire orders, —
nay, whole classes, which present an approximation to the state
of things here indicated.

If, when species have been thus placed in a regular series,
we select one, and then, making a leap over several interme-
diate ones, we take a second, at some distance from the first,
these two will, on comparison, be seen to be very dissimilar ;
and it is in this manner that every naturalist begins to study
the objects which are at his own door. He then finds it an
easy task to establish generic and specific distinctions ; and it
is only when his experience is enlarged, and when he has made
himself master of the intermediate links, that his difficulties
and ambiguities begin. But while we are thus compelled to
resort to trifling and minute characters in our attempt to sepa-
rate species, we find a striking disparity between individuals

Ch. I.] TRANSMUTATION OF SPECIES. 5

which we know to have descended from a common stock, and
these newly-acquired peculiarities are regularly transmitted
from one generation to another, constituting what are called
races.

From a great number of facts, continues the author, we learn
that; in proportion as the individuals of one of our species
change their situation, climate, and manner of living, they
change also, by little and little, the consistence and proportions
of their parts, their form, their faculties, and even their orga-
nization, in such a manner, that everything in them comes at
last to participate in the mutations to which they have been
exposed. Even in the same climate a great difference of
situation and exposure causes individuals to vary ; but if these
individuals continue to live and to be reproduced under the
same difference of circumstances, distinctions are brought
about in them which become in some degree essential to their
existence. In a word, at the end of many successive gene-
rations, these individuals, which originally belonged to another
species, are transformed into a new and distinct species *.

Thus, for example, if the seeds of a grass, or any other
plant which grows naturally in a moist meadow^ be acci-
dentally transported, first to the slope of some neighbouring
hill, where the soil, although at a greater elevation, is damp
enough to allow the plant to live ; and if, after having lived
there, and having been several times regenerated, it reaches
by degrees the drier and almost arid soil of a mountain
declivity, it will then, if it succeeds in growing and perpe-
tuates itself for a series of generations, be so changed that
botanists who meet with it will regard it as a particular spe-
ciesf . The unfavourable climate in this case, deficiency of
nourishment, exposure to the winds, and other causes, give
rise to a stunted and dwarfish race, with some organs more
developed than others, and having proportions often quite
peculiar.

* Phil. Zool. torn. i. p. 62.

t Ibid.

CHANGES IN ANIMALS AND PLANTS

[Ch, I.

What nature brings about in a great lapse of time we occasion
suddenly by changing the circumstances in which a species has
been accustomed to live. All are aware that vegetables taken
from their birth-place and cultivated in gardens, undergo
changes which render them no longer recognizable as the same
plants. Many which were naturally hairy become smooth
or nearly so ; a great number of such as were creepers and
trailed along the ground, rear their stalks and grow erect.
Others lose their thorns or asperities ; others again, from the
ligneous state which their stem possessed in hot climates'
where they were indigenous, pass to the herbaceous, and,
among them, some which were perennials become mere annuals.
So well do botanists know the effects of such changes of
circumstances, that they are averse to describe species from
garden specimens, unless they are sure that they have been cul-
tivated for a very short period.

e Is not the cultivated wheat,' (Triticum sativum) asks
Lamarck, ' a vegetable brought by man into the state in which
c we now see it ? Let any one tell me in what country a similar
e plant grows wild, unless where it has escaped from cultivated
e fields ? Where do we find in nature our cabbages, lettuces,
' and other culinary vegetables, in the state in which they
1 appear in our gardens ? Is it not the same in regard to
c a great quantity of animals which domesticity has changed
e or considerably modified * ? ' Our domestic fowls and
pigeons are unlike any wild birds. Our domestic ducks and
geese have lost the faculty of raising themselves into the higher
regions of the air, and crossing extensive countries in their flight,
like the wild ducks and wild geese from which they were
originally derived. A bird which we breed in a cage cannot,
when restored to liberty, fly like others of the same species
which have been always free. This small alteration of cir-
cumstances, however, has only diminished the power of flight,
without modifying the form of any part of the wings. But
when individuals of the same race are retained in captivity
- * Phil, Zool. torn. i. p. 227-

Ch. I.]

CAUSED BY DOMESTICATION.

during a considerable length of time, the form even of their
parts is gradually made to differ, especially if climate, nourish-
ment, and other circumstances, be also altered.

The numerous races of dogs which we have produced by
domesticity are nowhere to be found in a wild state. In
nature we should seek in vain for mastiffs, harriers, spaniels,
greyhounds, and other races, between which the differences are
sometimes so great, that they would be readily admitted as
specific between wild animals ; £ yet all these have sprung
£ originally from a single race, at first approaching very near
' to a wolf, if, indeed, the wolf be not the true type which at
* some period or other was domesticated by man.'

Although important changes in the nature of the places
which they inhabit modify the organization of animals as well
as vegetables, yet the former, says Lamarck, require more
time to complete a considerable degree of transmutation, and,
consequently, we are less sensible of such occurrences. Next
to a diversity of the medium in which animals or plants may
live, the circumstances which have most influence in modifying
their organs are differences in exposure, climate, the nature of
the soil, and other local particulars. These circumstances are
as varied as are the characters of species, and, like them, pass
by insensible shades into each other, there being every inter-
mediate gradation between the opposite extremes. But each
locality remains for a very long time the same, and is altered
so slowly that we can only become conscious of the reality of
the change, by consulting geological monuments, by which we
learn that the order of things which now reigns in each place
has not always prevailed, and by inference anticipate that it
will not always continue the same # .

Every considerable alteration in the local circumstances in
which each race of animals exists, causes a change in their wants,
and these new wants excite them to new actions and habits.
These actions require the more frequent employment of some
parts before but slightly exercised, and then greater develop-

* Phil. Zool. torn. i. p. 232.

lamarck's theory of the

[Ch. I.

ment follows as a consequence of their more frequent use.
Other organs no longer in use are impoverished and diminished
in size, nay, are sometimes entirely annihilated, while in their
place new parts are insensibly produced for the discharge of
new functions*.

We must here interrupt the author's argument, by observing
that no positive fact is cited to exemplify the substitution of
some entirely new sense, faculty, or organ, in the room of some
other suppressed as useless. All the instances adduced go
only to prove that the dimensions and strength of members
and the perfection of certain attributes may, in a long suc-
cession of generations, be lessened and enfeebled by disuse ;
or, on the contrary, be matured and augmented by active exer-
tion, just as we know that the power of scent is feeble in the
greyhound, while its swiftness of pace and its acuteness of sight
are remarkable — that the harrier and stag-hound, on the con-
trary, are comparatively slow in their movements, but excel in
the sense of smelling.

We point out to the reader this important chasm in the
chain of the evidence, because he might otherwise imagine
that we had merely omitted the illustrations for the sake of
brevity, but the plain truth is, that there were no examples to
be found ; and when Lamarck talks 4 of the efforts of internal
sentiment,' s the influence of subtle fluids,' and the 4 acts of
organization,' as causes whereby animals and plants may
acquire new organs, he gives us names for things, and with a
disregard to the strict rules of induction, resorts to fictions, as
ideal as the ' plastic virtue/ and other phantoms of the middle
ages.

It is evident, that if some well authenticated facts could
have been adduced to establish one complete step in the pro-
cess of transformation, such as the appearance, in individuals
descending from a common stock, of a sense or organ entirely
new, and a complete disappearance of some other enjoyed by
their progenitors, that time alone might then be supposed

* Phil. Zool. torn. i. p. 234,

Ch. I.]

TRANSMUTATION OF SPECIES.

sufficient to bring about any amount of metamorphosis. The
gratuitous assumption, therefore, of a point so vital to the
theory of transmutation, was unpardonable on the part of its
advocate.

But to proceed with the system ; it being assumed as an
undoubted fact, that a change of external circumstances may
cause one organ to become entirely obsolete, and a new one to
be developed such as never before belonged to the species, the
following proposition is announced, which, however staggering
and absurd it may seem, is logically deduced from the assumed
premises. " It is not the organs, or, in other words, the nature
and form of the parts of the body of an animal which have
given rise to its habits, and its particular faculties, but on
the contrary, its habits, its manner of living, and those of
its progenitors have in the course of time determined the
form of its body, the number and condition of its organs, in
short, the faculties which it enjoys. Thus otters, beavers,
water-fowl, turtles, and frogs, were not made web-footed in
order that they might swim ; but their wants having attracted
them to the water in search of prey, they stretched out the toes
of their feet to strike the water and move rapidly along its
surface. By the repeated stretching of their toes, the skin
which united them at the base acquired a habit of extension,
until in the course of time the broad membranes Avhich now
connect their extremities were formed.

In like manner the antelope and the gazelle were not
endowed with light agile forms, in order that they might
escape by flight from carnivorous animals j but having been
exposed to the danger of being devoured by lions, tigers, and
other beasts of prey, they were compelled to exert themselves
in running with great celerity, a habit which, in the course of
many generations, gave rise to the peculiar slenderness of
their legs, and the agility and elegance of their forms.

The cameleopard was not gifted with a long flexible neck
because it was destined to live in the interior of Africa, where
the soil was arid and devoid of herbage, but being reduced by

10 lamarck's theory op the . j-ch, i,

the nature of that country to support itself on the foliage of
lofty trees, it contracted a habit of stretching itself up to reach
the high boughs, until its fore-legs became longer than the
hinder, and its neck so elongated, that it could raise its head to
the height of twenty feet above the ground,"

Another line of argument is then entered upon, in farther
corroboration of the instability of species. In order it is said
that individuals should perpetuate themselves unaltered by
generation, those belonging to one species ought never to ally
themselves to those of another : but such sexual unions do take
place, both among plants and animals; and although the
offspring of such irregular connexions are usually sterile, yet
such is not always the case. Hybrids have sometimes proved
prolific where the disparity between the species was not too
great ; and by this means alone, says Lamarck, varieties may
gradually be created by near alliances, which would become
races, and in the course of time would constitute what we term
species*.

But if the soundness of all these arguments and inferences
be admitted, we are next to inquire, what were the original
types of form, organization, and instinct, from which the
diversities of character, as now exhibited by animals and plants,
have been derived ? We know that individuals which are
mere varieties of the same species, would, if their pedigree
could be traced back far enough, terminate in a single stock ;
so according to the train of reasoning before described, the
species of a genus, and even the genera of a great family, must
have had a common point of departure. What then was the
single stem from which so many varieties of form have rami-
fied ? Were there many of these, or are we to refer the origin
of the whole animate creation, as the Egyptian priests did
that of the universe, to a single egg ?

In the absence of any positive data for framing a theory on
so obscure a subject, the following considerations were deemed
of importance to guide conjecture.

f Phil. Zool p. 64.

Ch. I]

TRANSMUTATION OF SPECIES.

In the first place, if we examine the whole series of known
animals, from one extremity to the other, when they are arranged,
in the order of their natural relations, we find that we may pass
progressively, or at least with very few interruptions, from beings
of more simple to those of a more compound structure ; and in
proportion as the complexity of their organization increases, the
number and dignity of their faculties increase also. Among
plants a similar approximation to a graduated scale of being is
apparent. Secondly, it appears from geological observations,
that plants and animals of more simple organization existed on
the globe before the appearance of those of more compound
structure, and the latter were successively formed at later
periods : each new race being more fully developed than the
most perfect of the preceding era.

Of the truth of the last-mentioned geological theory, Lamarck
seems to have been fully persuaded ; and he also shews that he
was deeply impressed with a belief prevalent amongst the older
naturalists, that the primeval ocean "invested the whole
planet long after it became the habitation of living beings,
and thus he was inclined to assert the priority of the
types of marine animals to those of the terrestrial, and to
fancy, for example, that the testacea of the ocean existed first,
until some of them, by gradual evolution, were improved into
those inhabiting the land.

These speculative views had already been, in a great degree,
anticipated by Delametherie in his Teliamed, and by several
modern writers, so that the tables were completely turned on
the philosophers of antiquity, with whom it was a received
maxim, that created things were always most perfect when they
came first from the hands of their Maker, and that there was
a tendency to progressive deterioration in sublunary things
when left to themselves —

omnia fatis

In pejus ruere, ac retro sublapsa referri.

So deeply was the faith of the ancient schools of philosophy
imbued with this doctrine, that to check this universal prone-

lamarck's theory of the

[Ch. I.

ness to degeneracy, nothing less than the re-intervention of
the Deity was thought adequate; and it was held, that thereby
the order, excellence, and pristine energy of the moral and
physical world had been repeatedly restored.

But when the possibility of the indefinite modification of
individuals descending from common parents was once
assumed, as also the geological generalization respecting the
progressive development of organic life, it was natural that
the ancient dogma should be rejected, or rather reversed;
and that the most simple and imperfect forms and faculties
should be conceived to have been the originals whence all others
were developed. Accordingly , in conformity to these views, inert
matter was supposed to have been first endowed with life ; until
in the course of ages, sensation was superadded to mere vitality :
sight, hearing, and the other senses, were afterwards acquired ;
and then instinct and the mental faculties ; until, finally, by
virtue of the tendency of things to progressive improvement,
the irrational was developed into the rational.

The reader, however, will immediately perceive, that if all
the higher orders of plants and animals were thus supposed to
be comparatively modern, and to have been derived in a long
series of generations from those of more simple conformation,
some further hypothesis became indispensable, in order to ex-
plain why, after an indefinite lapse of ages, there were still so
many beings of the simplest structure. Why have the ma-
jority of existing creatures remained stationary throughout
this long succession of epochs, while others have made such
prodigious advances ? Why are there still such multitudes of
infusoria and polypes, or of confervas and other cryptogamic
plants ? Why, moreover, has the process of development
acted with such unequal and irregular force on those classes of
beings which have been greatly perfected, so that there are
wide chasms in the series ; gaps so enormous, that Lamarck
fairly admits we can never expect to fill them up by future
discoveries ?

The following hypothesis was provided to meet these objec-

Ch. I.]

TRANSMUTATION OF SPECIES.

tions. Nature, we are told, is not an intelligence, nor the
Deity, but a delegated power — a mere instrument — a piece
of mechanism acting by necessity — an order of things con-
stituted by the Supreme Being, and subject to laws which
are the expressions of his will. This nature is obliged to
proceed gradually in all her operations ; she cannot produce
animals and plants of all classes at once, buj; must always
begin by the formation of the most simple kinds; and
out of them elaborate the more compound, adding to them
successively, different systems of organs, and multiplying
more and more their number and energy.

This Nature is daily engaged in the formation of the elemen-
tary rudiments of animal and vegetable existence, which cor-
respond to what the ancients termed spontaneous generations.
She is always beginning anew, day by day, the work of creation,
by forming monads, or ' rough draughts' (ebauches), which are
the only living things she ever gives birth to directly.

There are distinct primary rudiments of plants and animals,
and probably of each of the great divisions of the animal and
vegetable kingdoms *. These are gradually developed into the
higher and more perfect classes by the slow, but unceasing
agency of two influential principles : first, the tendency to
progressive advancement in organization, accompanied by
greater dignity in instinct, intelligence, &c. ; secondly, the force
of external circumstances, or of variations in the physical con-
dition of the earth, or the mutual relations of plants and ani-
mals. For as species spread themselves gradually over the
globe, they are exposed from time to time to variations in
climate, and to changes in the quantity and quality of their
food ; they meet with new plants and animals which assist or
retard their development, by supplying them w r ith nutriment,
or destroying their foes. The nature also of each locality is
in itself fluctuating, so that even if the relation of other
animals and plants were invariable, the habits and organization

* Auimaux sans Vert., torn. i. p. 56, Introduction.

CONVERSION OF THE ORANG-OUTANG

[Ch. I.

of species would be modified by the influence of local revolu-
tions.

Now, if the first of these principles, the tendency to pro-
gressive development, were left to exert itself with perfect
freedom, it would give rise, says Lamarck, in the course of
ages, to a graduated scale of being, where the most insensible
transition might be traced from the simplest to the most com-
pound structure, from the humblest to the most exalted degree
of intelligence. But in consequence of the perpetual inter-
ference of the external causes before mentioned, this regular
order is greatly interfered with, and an approximation only to
such a state of things is exhibited by the animate creation,
the progress of some races being retarded by unfavourable,
and that of others accelerated by favourable, combinations of
circumstances. Hence, all kinds of anomalies interrupt the
continuity of the plan, and chasms, into which whole genera or
families might be inserted, are seen to separate the nearest
existing portions of the series.

Such is the machinery of the Lamarckian system ; but our
readers will hardly, perhaps, be able to form a perfect concep-
tion of so complicated a piece of mechanism, unless we exhibit
it in motion, and shew in what manner it can work out, under
the author's guidance, all the extraordinary effects which we
Jbehold in the present state of the animate creation. We have
only space for exhibiting a small part of the entire process by
which a complete metamorphosis is achieved, and shall, there-
fore, omit the mode whereby, after a countless succession of
generations, a small gelatinous body is transformed into an
oak or an ape. We pass on at once to the last grand step in
the progressive scheme, whereby the orang-outang, having
been already evolved out of a monad, is made slowly to attain
the attributes and dignity of man.

One of the races of quadrumanous animals which had
reached the highest state of perfection, lost, by constraint of
circumstances, (concerning the exact nature of which tradition
is unfortunately silent,) the habit of climbing trees, and of

Ch. I.]

INTO THE HUMAN SPECIES.

hanging on. by grasping the boughs with their feet as with
hands. The individuals of this race being obliged for a long
series of generations to use their feet exclusively for walking,
and ceasing to employ their hands as feet, were transformed
into bimanous animals, and what before were thumbs became
mere toes, no separation being required when their feet were
used solely for walking. Having acquired a habit of holding
themselves upright, their legs and feet assumed insensibly a
conformation fitted to support them in an erect attitude, till at
last these animals could no longer go on all fours without much
inconvenience.

The Angola orang, Simia troglodytes, Linn., is the most
perfect of animals, much more so than the Indian orang,
Simia Satyrus, which has been called the orang-outang,
although both are very inferior to man in corporeal powers
and intelligence. These animals frequently hold themselves
upright, but their organization has not yet been sufficiently
modified to sustain them habitually in this attitude, so that
the standing posture is very uneasy to them. When the Indian
orang is compelled to take flight from pressing danger, he im-
mediately falls down upon all fours, shewing clearly that this
was the original position of the animal. Even in man, whose
organization, in the course of a long series of generations, has
advanced so much farther, the upright posture is fatiguing
and can only be supported for a limited time, and by aid of
the contraction of many muscles. If the vertebral column
formed the axis of the human body, and supported the head
and all the other parts in equilibrium, then might the upright
position be a state of repose ; but as the human head does not
articulate in the centre of gravity; as the chest, belly, and other
parts, press almost entirely forward with their whole weight,
and as the vertebral column reposes upon an oblique base, a
watchful activity is required to prevent the body from falling.
Children which have large heads and prominent bellies can
hardly walk at the end even of two years, and their frequent

CONVERSION OF THE ORANG-OUTANG

[Ch. I.

tumbles indicate the natural tendency in man to resume the
quadrupedal state.

Now, when so much progress had been made by the quadru-
manous animals before mentioned, that they could hold them-
selves habitually in an erect attitude, and were accustomed to
a wide range of vision, and ceased to use their jaws for fighting,
and tearing, or for clipping herbs for food, their snout became
gradually shorter, their incisor teeth became vertical, and the
facial angle grew more open.

Among other ideas which the natural tendency to perfection
engendered, the desire of ruling suggested itself, and this race
succeeded at length in getting the better of the other animals,
and made themselves masters of all those spots on the surface
of the globe which best suited them. They drove out the
animals which approached nearest to them in organization and
intelligence, and which were in a condition to dispute with
them the good things of this world, forcing them to take
refuge in deserts, woods and wildernesses, where their multi-
plication was checked, and the progressive development of
their faculties retarded, while in the mean time the dominant
race spread itself in every direction, and lived in large com-
panies where new wants were successively created, exciting
them to industry, and gradually perfecting their means and
faculties.

In the supremacy and increased intelligence acquired by the
ruling race, we see an illustration of the natural tendency of
the organic world to grow more perfect, and in their influence
in repressing the advance of others, an example of one of those
disturbing causes before enumerated, that force of external cir-
cumstances, which causes such wide chasms in the regular series
of animated beings.

When the individuals of the dominant race became very
numerous, their ideas greatly increased in number, and they
felt the necessity of communicating them to each other, and
of augmenting and varying the signs proper for the commu-

Ch. I.]

INTO THE HUMAN SPECIES.

nication of ideas. Meanwhile the inferior quadrumanous
animals, although most of them were gregarious, acquired
no new ideas, being persecuted and restless in the deserts,
and obliged to fly and conceal themselves, so that they
conceived no new wants. Such ideas as they already had
remained unaltered, and they could dispense with the com-
munication of the greater part of these. To make them-
selves, therefore, understood by their fellows, required merely
a few movements of the body or limbs- — whistling, and the
uttering of certain cries varied by the inflexions of the voice.

On the contrary, the individuals of the ascendant race, ani-
mated with a desire of interchanging their ideas, which became
more and more numerous, were prompted to multiply the means
of communication, and were no longer satisfied with mere pan-
tomimic signs, nor even with all the possible inflexions of the
voice, but made continual efforts to acquire the power of
uttering articulate sounds, employing a few at first, but after-
wards varying and perfecting them according to the increase
of their wants. The habitual exercise of their throat, tongue
and lips, insensibly modified the conformation of these organs,
until they became fitted for the faculty of speech*.

In effecting this mighty change, " the exigencies of the indi-
viduals were the sole agents, they gave rise to efforts, and the
organs proper for articulating sounds were developed by their
habitual employment." Hence, in this peculiar race, the
origin of the admirable faculty of speech ; hence also the diver-
sity of languages, since the distance of places where the indi-
viduals composing the race established themselves, soon fa-
voured the corruption of conventional signs -f*.

* Lamarck's Phil. Zool., torn. i. p. 356. f Ibid. p. 357.

Vol. II.

CHAPTER II.

Recapitulation of the arguments in favour of the theory of transmutation of species
— Their insufficiency — The difficulty of discriminating species mainly attribu-
table to a defective knowledge of their history — Some mere varieties possibly
more distinct than certain individuals of distinct species — Variability in a
species consistent with a belief that the limits of deviation are fixed — No facts
of transmutation authenticated — Varieties of the Dog — The Dog and Wolf
distinct species — Mummies of various animals from Egypt identical in cha-
racter with living individuals — Seeds and plants from the Egyptian tombs — ,
Modifications produced in plants by agriculture and gardening.

The theory of the transmutation of species, considered in the
last chapter, has met with some degree of favour from many
naturalists, from their desire to dispense, as far as possible,
with the repeated intervention of a First Cause, as often
as geological monuments attest the successive appearance of
new races of animals and plants, and the extinction of those
pre-existing. But, independently of a predisposition to account,
if possible, for a series of changes in the organic world, by the
regular action of secondary causes, we have seen that many
perplexing difficulties present themselves to one who attempts
to establish the nature and the reality of the specific character.
And if once there appears ground of reasonable doubt, in
regard to the constancy of species, the amount of transform-
ation which they are capable of undergoing, may seem to
resolve itself into a mere question of the quantity of time
assigned to the past duration of animate existence.

Before we enter upon our reasons for rejecting Lamarck's
hypothesis, we shall recapitulate, in a few words, the pheno-
mena, and the whole train of thought, by which we conceive
it to have been suggested, and which have gained for this and
analogous theories, both in ancient and modern times, a con-
siderable number of votaries.

In the first place, the various groups into which plants and

Ch. II.] PERMANENCE OF THE SPECIFIC CHARACTER.

animals may be thrown, seem almost invariably, to a beginner,
to be so natural, that he is usually convinced at first, as was
Linnaeus to the last, u that genera are as much founded in
nature as the species which compose them # ." When, by exa^-
mining the numerous intermediate gradations, the student finds
all lines of demarcation to be in most instances obliterated,
even where they at first appeared most distinct, he grows more
and more sceptical as to the real existence of genera, and finally
regards them as mere arbitrary and artificial signs, invented
like those which serve to distinguish the heavenly constellations
for the convenience of classification, and having as little pre-
tensions to reality.

Doubts are then engendered in his mind as to whether
species may not also be equally unreal. The student is
probably first struck with the phenomenon, that some indi-
viduals are made to deviate widely from the ordinary type
by the force of peculiar circumstances, and with the still
more extraordinary fact, that the newly-acquired peculiarities
are faithfully transmitted to the offspring. How far, he asks,
may such variations extend in the course of indefinite periods
of time, and during great vicissitudes in the physical condition
of the globe ? His growing incertitude is at first checked by
the reflection, that nature has forbidden the intermixture of the
descendants of distinct original stocks, or has, at least, entailed
sterility on their offspring, thereby preventing their being
confounded together, and pointing out that a multitude of dis-
tinct types must have been created in the beginning, and must
have remained pure and uncorrupted to this clay.

Relying on this general law, he endeavours to solve each dif-
cult problem by direct experiment, until he is again astounded by
the phenomenon of a prolific hybrid, and still more by an example
of a hybrid perpetuating itself throughout several generations
in the vegetable world. He then feels himself reduced to the
dilemma of choosing between two alternatives, either to reject
the test, or to declare that the two species, from the union of

* Sir J. Smith's Introduction to Botany.

C 2

PERMANENCE OF THE SPECIFIC CHARACTER. [Ch. II.

which the fruitful progeny has sprung, were mere varieties.
If he prefer the latter, he is compelled to question the reality
of the distinctness of all other supposed species which differ no
more than the parents of such prolific hybrids ; for although
he may not be enabled immediately to procure, in all such
instances, a fruitful offspring, yet experiments show, that after
repeated failures the union of two recognized species may at
last, under very favourable circumstances, give birth to a fertile
progeny. Such circumstances, therefore, the naturalist may
conceive to have occurred again and again, in the course of a
great lapse of ages.

His first opinions are now fairly unsettled, and every stay
at which he has caught has given way one after another ; he
is in danger of falling into any new and visionary doctrine
which may be presented to him ; for he now regards every part
of the animate creation as void of stability, and in a state of
continual flux. In this mood he encounters the Geologist, who
relates to him how there have been endless vicissitudes in the
shape and structure of organic beings in former ages — how the
approach to the present system of things has been gradual —
that there has been a progressive development of organization
subservient to the purposes of life, from the most simple to the
most complex state — that the appearance of man is the last
phenomenon in a long succession of events — and, finally, that a
series of physical revolutions can be traced in the inorganic
world, coeval and coextensive with those of organic nature.

These views seem immediately to confirm all his precon-
ceived doubts as to the stability of the specific character, and he
thinks he can discern an inseparable connexion between a series
of changes in the inanimate world, and the capability of species
to be indefinitely modified by the influence of external circum-
stances. Henceforth his speculations know no definite bounds ;
he gives the rein to conjecture, and fancies that the outward
form, internal structure, instinctive faculties, nay, that reason
itself, may have been gradually developed from some of the
simplest states of existence, — that all animals, that man him-

Ch. II.] PERMANENCE OF THE SPECIFIC CHARACTER. 21

self, and the irrational beings, may have had one common
origin ; that all may be parts of one continuous and progres-
sive scheme of development from the most imperfect to the
more complex ; in fine, he renounces his belief in the high
genealogy of his species^ and looks forward., as if in compensation,
to the future perfectibility of man in his physical, intellectual,
and moral attributes.

Let us now proceed to consider what is defective in evi-
dence, and what fallacious in reasoning, in the grounds of these
strange conclusions. Blumenbach judiciously observes, " that
no general rule can be laid down for determining the distinct-
ness of species, as there is no particular class of characters
which can serve as a criterion. In each case we must be
guided by analogy and 'probability The multitude, in fact,
and complexity of the proofs to be weighed, is so great, that
we can only hope to obtain presumptive evidence, and we
must, therefore, be the more careful to derive our general
views as much as possible from those observations where the
chances of deception are least. We must be on our guard
not to tread in the footsteps of the naturalists of the middle
ages, who believed the doctrine of spontaneous generation to
be applicable to all those parts of the animal and vegetable
kingdoms which they least understood, in direct contradiction
to the analogy of all the parts best known to them ; and who,
when at length they found that insects and cryptogamous plants
were also propagated from eggs and seeds, still persisted in
retaining their old prejudices respecting the infusory animal-
cules and other minute beings, the generation of which had
not then been demonstrated by the microscope to be governed
by the same laws.

Lamarck has indeed attempted to raise an argument in favour
of his system, out of the very confusion which has arisen in the
study of some orders of animals and plants, in consequence of
the slight shades of difference which separate the new species
discovered within the last half century. That the embarrass-
ment of those who attempt to classify and distinguish the new

CAUSES OF THE DIFFICULTY

[Ch. II.

acquisitions poured in such multitudes into our museums,
should increase with the augmentation of their number is quite
natural ; for to obviate this it is not enough that our powers of
discrimination should keep pace with the increase of the objects,
but we ought to possess greater opportunities of studying each
animal and plant in all stages of its growth, and to know pro-
foundly their history, their habits and physiological characters,
throughout several generations. For, in proportion as the series
of known animals grows more complete, none can doubt that
there is a nearer approximation to a graduated scale of being ;
and thus the most closely allied species will possess a greater
number of characters in common.

But, in point of fact, our new acquisitions consist, more
and more as we advance, of specimens brought from foreign
and often very distant and barbarous countries. A large
proportion have never even been seen alive by scientific
inquirers. Instead of having specimens of the young, the
adult, and the aged individuals of each sex, and possessing
means of investigating the anatomical structure, the peculiar
habits and instincts of each, what is usually the state of our
information ? A single specimen, perhaps, of a dried plant, or
a stuffed bird or quadruped ; a shell without the soft parts of
the animal ; an insect in one stage of its numerous transforma-
tions ; these are the scanty and imperfect data, which the
naturalist possesses. Such information may enable us to
separate species which stand at a considerable distance from
each other ; but we have no right to expect anything but diffi-
culty and ambiguity, if we attempt, from such imperfect oppor-
tunities, to obtain distinctive marks for defining the characters
of species, which are closely related.

If Lamarck could introduce so much certainty and precision
into the classification of several thousand species of recent and
fossil shells, notwithstanding the extreme remoteness of the
organization of these animals from the type of those vertebrated
species which are best known, and in the absence of so many
of the living inhabitants of shells, we are led to form an exalted

Ch. II.]

OF DISCRIMINATING SPECIES.

conception of the degree of exactness to which specific dis-
tinctions are capable of being carried, rather than to call in
question their reality.

When our data are so defective, the most acute naturalist
must expect to be sometimes at fault, and, like the novice, to
overlook essential points of difference, passing unconsciously
from one species to another, until, like one who is borne along
in a current, he is astonished, on looking back, at observing
that he has reached a point so remote from that whence he set
out.

It is by no means improbable that when the series of species
of certain genera is very full, they may be found to differ less
widely from each other, than do the mere varieties or races of
certain species. If such a fact could be established, it would
by no means overthrow our confidence in the reality of species,
although it would certainly diminish the chance of our ob-
taining certainty in our results.

It is almost necessary, indeed, to suppose, that varieties will
differ in some cases, more decidedly than some species, if we
admit that there is a graduated scale of being, and assume that
the following laws prevail in the economy of the animate crea-
tion : — first, that the organization of individuals is capable of
being modified to a limited extent by the force of external
causes ; secondly, that these modifications are, to a certain ex-
tent, transmissible to their offspring; thirdly, that there are
fixed limits beyond which the descendants from common
parents can never deviate from a certain type; fourthly, that
each species springs from one original stock, and can never
be permanently confounded, by intermixing with the progeny"
of any other stock ; fifthly, that each species shall endure for
a considerable period of time. Now if we assume, for the pre-
sent, these rules hypothetical^ let us see what consequences
may naturally be expected to result.

We must suppose, that when the Author of Nature creates
an animal or plant, all the possible circumstances in which its
descendants are destined to live are foreseen, and that an

CAUSES OF VARIABILITY

[Ch. II.

organization is conferred upon it which will enable the species
to perpetuate itself and survive under all the varying circum-
stances to which it must be inevitably exposed. Now the
range of variation of circumstances will differ essentially in
almost every case. Let us take for example any one of the
most influential conditions of existence, such as temperature.
In some extensive districts near the equator, the thermo-
meter might never vary throughout several thousand centuries
for more than 20° Fahrenheit ; so that if a plant or animal
be provided with an organization fitting it to endure such
a range, it may continue on the globe for that immense
period, although every individual might be liable at once to be
cut off by the least possible excess of heat or cold beyond the
determinate quantity. But if a species be placed in one of the
temperate zones, and have a constitution conferred on it
capable of supporting a similar range of temperature only, it
will inevitably perish before a single year has passed away.

The same remark might be applied to any other con-
dition, as food for example; it may be foreseen that the
supply will be regular throughout indefinite periods in one
part of the world, and in another very precarious and fluc-
tuating both in kind and quantity. Different qualifications
may be required for enabling species to live for a considerable
time under circumstances so changeable. If, then, temperature
and food be among those external causes, which according to
certain laws of animal and vegetable physiology modify the
organization, form, or faculties of individuals, we instantly
perceive that the degrees of variability from a common
standard must differ widely in the two cases above supposed,
since there is a necessity of accommodating a species in one case
to a much greater latitude of circumstances than in the other.

If it be a law, for instance, that scanty sustenance should
check those individuals in their growth which are enabled
to accommodate themselves to privations of this kind, and
that a parent prevented in this manner from attaining the
size proper to its species should produce a dwarfish offspring,

Ch. II,]

IN THE SAME SPECIES.

a stunted race will arise, as is remarkably exemplified in some
varieties of the horse and dog. The difference of stature in
some races of dogs in comparison to others, is as one to five in
linear dimensions, making a difference of a hundred-fold in
volume *« Now there is good reason to believe that species in
general are by no means susceptible of existing under a diver-
sity of circumstances, which may give rise to such a disparity in
size, and consequently, there will be a multitude of distinct spe-
cies, of which no two adult individuals can ever depart so widely
from a certain standard of dimensions as the mere varieties of
certain other species, — the dog for instance. Now we have only
to suppose that what is true of size, may also hold in regard to
colour and many other attributes, and it will at once follow
that the degree of possible discordance between varieties of the
same species, may in certain cases exceed the utmost dis-
parity which can even arise between two individuals of many
distinct species.

The same remarks may hold true in regard to instincts ; for
if it be foreseen that one species will have to encounter a great
variety of foes, it may be necessary to arm it with great
cunning and circumspection, or with courage or other quali-
ties capable of developing themselves on certain occasions; such
for example as those migratory instincts which are so remark-
ably exhibited at particular periods, after they have remained
dormant for many generations. The history and habits
of one variety of such a species^ may often differ more con-
siderably from some other than those of many distinct species
which have no such latitude of accommodation to circum-
stances.

Lamarck has somewhat misstated the idea commonly enter-
tained of a species, for it is not true that naturalists in general
assume that the organization of an animal or plant remains
absolutely constant, and that it can never vary in any of
its parts. All must be aware that circumstances influence the
habits, and that the habits may alter the state of the parts and

* Cuvier, Disc, Prelim., p. 128, sixth edition.

EXTENT OF KNOWN

[Ch. II.

organs *. But the difference of opinion relates to the extent
to which these modifications of the habits and organs of a
particular species may be carried.

Now let us first inquire what positive facts can be adduced
in the history of known species, to establish a great and per-
manent amount of change in the form, structure, or instinct
of individuals descending from some common stock. The
best authenticated examples of the extent to which species can
be made to vary, may be looked for in the history of domes-
ticated animals and cultivated plants. It usually happens that
those species, both of the animal and vegetable kingdom, which
have the greatest pliability of organization, those which are
most capable of accommodating themselves to a great variety
of new circumstances, are most serviceable to man. These
only can be carried by him into different climates, and can have
their properties or instincts variously diversified by differences
of nourishment and habits. If the resources of a species be so
limited, and its habits and faculties be of such a confined and
local character, that it can only flourish in a few particular
spots, it can rarely be of great utility.

We may consider, therefore, that in perfecting the arts of
domesticating animals and cultivating plants, mankind have first
selected those species which have the most flexible frames and
constitutions, and have then been engaged for ages in conduct-
ing a series of experiments, with much patience and at great cost,
to ascertain what may be the greatest possible deviation from a
common type which can be elicited in these extreme cases.

The modifications produced in the different races of dogs,
exhibit the influence of man in the most striking point of view.
These animals have been transported into every climate, and
placed in every variety of circumstances; they have been made,
as a modern naturalist observes, the servant, the companion,
the guardian, and the intimate friend of man, and the power of
a superior genius has had a wonderful influence, not only on

* Phil. Zool.,tom.i.p. 266.

Ch. II.]

VARIABILITY IN SPECIES.

their forms, but on their manners and intelligence*. Dif-
ferent races have undergone remarkable changes in the quan-
tity and colour of their clothing: the dogs of Guinea are
almost naked, while those of the Arctic circle are covered with
a warm coat both of hair and wool, which enables them to
bear the most intense cold without inconvenience. There are
differences also of another kind no less remarkable, as in size,
the length of their muzzles, and the convexity of their fore-
heads.

But if we look for some of those essential changes which
would be required to lend even the semblance of a foun-
dation for the theory of Lamarck, respecting the growth of
new organs and the gradual obliteration of others, we find
nothing of the kind. For in all these varieties of the dog,
says Cuvier, the relation of the bones with each other remain
essentially the same ; the form of the teeth never changes in
any perceptible degree, except that in some individuals, one
additional false grinder occasionally appears, sometimes on
the one side, and sometimes on the other -f. The greatest
departure from a common type, and it constitutes the maxi-
mum of variation as yet known in the animal kingdom, is
exemplified in those races of dogs which have a supernu-
merary toe on the hind foot with the corresponding tarsal
bones, a variety analogous to one presented by six-fingered
families of the human race J.

Lamarck has thrown out as a conjecture, that the wolf may
have been the original of the dog, but he has adduced no
data to bear out such an hypothesis. " The wolf," observes
Dr. Prichard, " and the dog differ, not only with respect to
their habits and instincts, which in the brute creation are very
uniform within the limits of one species ; but some differences
have also been pointed out in their internal organization,

* Dureau de la Malle, Ann. des. Sci. Nat. torn. xxi. p. 63. Sept. 1830.
f Disc. Prel,, p. 129, sixth edition, t Ibid,

28 EGYPTIAN MUMMIES IDENTICAL [Ch. II.

particularly in the structure of a part of the intestinal
canal*."

It is well known that the horse, the ox, the boar and other
domestic animals, which have been introduced into South
America, and have run wild in many parts, have entirely lost
all marks of domesticity, and have reverted to the original
characters of their species. But the dog has also become wild in
Cuba, Hayti, and in all the Caribbean islands; In the course
of the seventeenth century, they hunted in packs from twelve
to fifty, or more in number, and fearlessly attacked herds of
wild-boars and other animals. It is natural, therefore, to
enquire to what form they reverted ? Now they are said by
many travellers to have resembled very nearly the shepherd's
dog; but it is certain that they were never turned into wolves.
They were extremely savage, and their ravages appear to have
been as much dreaded as those of wolves, but when any of
their whelps were caught, and brought from the woods to the
towns, they grew up in the most perfect submission to man.

As the advocates of the theory of transmutation trust much
to the slow and insensible changes which time may work, they
are accustomed to lament the absence of accurate descriptions,
and figures of particular animals and plants, handed down
from the earliest periods of history,, such as might have afforded
data for comparing the condition of species, at two periods
considerably remote. But fortunately, we are in some measure
independent of such evidence, for by a singular accident, the
priests of Egypt have bequeathed to us, in their cemeteries,
that information, which the museums and works of the Greek
philosophers have failed to transmit.

Eor the careful investigation of these documents, we are
greatly indebted to the skill and diligence of those naturalists
who accompanied the French armies during their brief occu-
pation of Egypt : that conquest of four years, from which we
may date the improvement of the modern Egyptians in the arts

* Prichard, Phys. Hist, of Maulutid, vol i. p. 96, who cites Professor Giildenstadt.

Ch. II.] WITH SPECIES STILL LIVING. 29

and sciences, and the rapid progress which has been made of
late in our knowledge of the arts and sciences of their remote
predecessors. Instead of wasting their whole time as so
many preceding, travellers had done, in exclusively collecting
human mummies, M. Geoffrey and his associates examined
diligently, and sent home great numbers of embalmed bodies
of consecrated animals, such as the bull, the dog, the cat, the
ape, the ichneumon, the crocodile, and the ibis.

To those who have never been accustomed to connect the
facts of Natural History with philosophical speculations, who
have never raised their conceptions of the end and import
of such studies beyond the mere admiration of isolated and
beautiful objects, or the exertion of skill in detecting specific
differences, it will seem incredible that amidst the din of arms,
and the stirring excitement of political movements, so much
enthusiasm could have been felt in regard to these precious
remains.

In the official report drawn up by the Professors of the
Museum at Paris, on the value of these objects, there are
some eloquent passages which may appear extravagant, unless
we reflect how fully these naturalists could appreciate the bear-
ing of the facts thus brought to light on the past history of the
globe.

"It seems," say they, " as if the superstition of the ancient
Egyptians had been inspired by Nature, with a view of trans-
mitting to after ages a monument of her history. That extraor-
dinary and whimsical people, by embalming with so much care
the brutes which were the objects of their stupid adoration, have
left us, in their sacred grottoes, cabinets of zoology almost com-
plete. The climate has conspired with the art of embalming to
preserve the bodies from corruption, and we can now assure
ourselves by our own eyes what was the state of a great number
of species three thousand years ago. We can scarcely restrain
the transports of our imagination, on beholding thus preserved
with their minutest bones, with the smallest portions of their
skin, and in every particular most perfectly recognizable, many

30 EGYPTIAN MUMMIES IDENTICAL [Ch. II.

an animal, which at Thebes or Memphis, two or three thousand
years ago, had its own priests and altars *."

Among the Egyptian mummies thus procured were not only
those of numerous wild quadrupeds, birds, and reptiles, but,
what was perhaps of still greater importance in deciding the
great question under discussion, there were the mummies of
domestic animals, among which those above mentioned, the
bull, the dog, and the cat^ were frequent. Now such was the
conformit} r of the whole of these species to those now living,
that there was no more difference, says Cuvier, between them
than between the human mummies and the embalmed bodies
of men of the present day. Yet some of these animals have
since that period been transported by man to almost every
variety of climate, and forced to accommodate their habits to
new circumstances, as far as their nature would permit. The
cat, for example, has been carried over the whole earth, and,
within the last three centuries, has been naturalized in every
part of the new worlds from the cold regions of Canada to the
tropical plains of Guiana ; yet it has scarcely undergone any
perceptible mutation, and is still the same animal which was
held sacred by the Egyptians.

Of the ox, undoubtedly there are many very distinct races ;
but the bull Apis, which was led in solemn processions by the
Egyptian priests, did not differ from some of those now living.
The black cattle that have run wild in America, where there
were many peculiarities in the climate not to be found, perhaps,
in any part of the old world, and where scarcely a single plant
on which they fed was of precisely the same species, instead of
altering their form and habits, have actually reverted to the
exact likeness of the aboriginal wild cattle of Europe.

In answer to the arguments drawn from the Egyptian mum-
mies, Lamarck said that they were identical with their living
descendants in the same country, because the climate and

* Ami. du Museum, d'Hist. Nat., torn. i. p. 234. 1802. The reporters were
MM. Cuvier, LacSpede, and Lamarck.

Ch, II.]

WITH SPECIES STILL LIVING.

physical geography of the banks of the Nile have remained
unaltered for the last thirty centuries. But why, we ask,
have other individuals of these species retained the same cha-
racters in so many different quarters of the globe, where the
climate and many other conditions are so varied ?

The evidence derived from the Egyptian monuments was
not confined to the animal kingdom ; the fruits, seeds, and
other portions of twenty different plants, were faithfully pre-
served in the same manner ; and anions; these the common
wheat was procured by Delille, from closed vessels in the
sepulchres of the kings, the grains of which retained not only
their form, but even their colour, so effectual has proved the
process of embalming with bitumen in a dry and equable
climate. No difference could be detected between this wheat
and that which now grows in the East and elsewhere, and
similar identifications were made in regard to all the other
plants.

And here we may observe, that there is an obvious answer
to Lamarck's objection *, that the botanist cannot point out
a country where the common wheat grows wild, unless in
places where it may have been derived from neighbouring
cultivation. All naturalists are well aware that the geogra-
phical distribution of a great number of species is extremely
limited, and that it was to be expected that every useful plant
should first be cultivated successfully in the country where it
was indigenous, and that, probably, every station which it par-
tially occupied, when growing wild, would be selected by the
agriculturist as best suited to it when artificially increased.
Palestine has been conjectured, by a late writer on the Cerealia,
to have been the original habitation of wheat and barley, a
supposition which appears confirmed by Hebrew and Egyptian
traditions, and by tracing the migrations of the worship of
Ceres, as indicative of the migrations of the plant f.

If we are to infer that some one of the wild grasses has been

* Phil. Zool., torn, i., p. 227.
f L'Orighie et la Patrie des Cereales, &c. Ann.des Sci.Nat,, torn, ix., p. 61.

VARIETIES IN PLANTS

[Ch. II.

transformed into the common wheat, and that some animal of
the genus canis, still unreclaimed, has been metamorphosed
into the dog, merely because we cannot find the domestic dog,
or the cultivated wheat, in a state of nature, we may be next
called upon to make similar admissions in regard to the camel;
for it seems very doubtful whether any race of this species of
quadruped is now wild.

But if agriculture, it will be said, does not supply examples
of extraordinary changes of form and organization, the horti-
culturist can, at least, appeal to facts which may confound
the preceding train of reasoning. The crab has been trans-
formed into the apple ; the sloe into the plum : flowers have
changed their colour and become double ; and these new cha-
racters can be perpetuated by seed, — a bitter plant with wavy
sea-green leaves has been taken from the sea-side where it grew
like wild charlock, has been transplanted into the garden, lost its
saltness, and has been metamorphosed into two distinct vege-
tables as unlike each other as is each to the parent plant — the
red cabbage and the cauliflower. These, and a multitude of
analogous facts, are undoubtedly among the wonders of nature,
and attest more strongly, perhaps, the extent to which species
may be modified, than any examples derived from the animal
kingdom. But in these cases we find, that we soon reach cer-
tain limits, beyond which we are unable to cause the indivi-
duals, descending from the same stock, to vary; while, on the
other hand, it is easy to show that these extraordinary varieties
could seldom arise, and could never be perpetuated in a wild
state for many generations, under any imaginable combination
of accidents. They may be regarded as extreme cases brought
about by human interference, and not as phenomena which
indicate a capability of indefinite modification in the natural
world.

The propagation of a plant by buds or grafts, and by cut-
tings, is obviously a mode which nature does not employ ; and
this multiplication, as well as that produced by roots and layers,
seems merely to operate as an extension of the life of an indivi-

Ch. II.]

PRODUCED BY HORTICULTURE.

dual, and not as a reproduction of the species, as happens by
seed. All plants increased by the former means retain pre-
cisely the peculiar qualities of the individual to which they
owe their origin, and, like an individual, they have only a
determinate existence ; in some cases longer and in others
shorter *. It seems now admitted by horticulturists, that
none of our garden varieties of fruit are entitled to be con-
sidered strictly permanent, but that they wear out after a
time | ; and we are thus compelled to resort again to seeds ;
in which case, there is so decided a tendency in the seedlings
to revert to the original type, that our utmost skill is some-
times baffled in attempting to recover the desired variety.

The different races of cabbages afford, as we have admitted,,
an astonishing example of deviation from a common type ; but
we can scarcely conceive them to have originated, much less to
have lasted for several generations, without the intervention of
man. It is only by strong manures that these varieties have
been obtained, and in poorer soils they instantly degenerate.
If, therefore, we suppose in a state of nature the seed of the
wild Brassica oleracea to have been wafted from the sea-side
to some spot enriched by the dung of animals, and to have there
become a cauliflower, it would soon diffuse its seed to some
comparatively steril soils around, and the offspring would
relapse to the likeness of the parent stock, like some indivi-
duals which may now be seen growing on the cornice of old
London bridge.

But if we go so far as to imagine the soil, in the spot
first occupied, to be constantly manured by herds of Avild
animals, so as to continue as rich as that of a garden, still the
variety could not be maintained, because we know that each of
these races is prone to fecundate others, and gardeners are
compelled to exert the utmost diligence to prevent cross-breeds.
The intermixture of the pollen of varieties growing in the
poorer soil around, would soon destroy the peculiar characters

* Smith's Introduction to Botany, p. 138. Edit. IS07.
f See Mr. Knight's Observations, Hort, Trans., vol, p. 160.
Vol. II. D

VARIETIES IN PLANTS

[Ch. II.

of the race which occupied the highly-manured tract ; for, if
these accidents so continually happen in spite of us, among
the culinary vai'ieties, it is easy to see how soon this cause
might obliterate every marked singularity in a wild state.

Besides, it is well-known that although the pampered races
which we rear in our gardens for use or ornament, may
often be perpetuated by seed, yet they rarely produce seed
in such abundance, or so prolific in quality, as wild individuals ;
so that, if the care of man were withdrawn, the most fertile
variety would always, in the end, prevail over the more steril.

Similar remarks may be applied to the double flowers which
present such strange anomalies to the botanist. The ovarium,
in such cases, is frequently abortive, and the seeds, when pro-
lific, are generally much fewer than where the flowers are
single.

Some curious experiments recently made on the production
of blue instead of red flowers in the Hydrangea hortensis,
illustrate the immediate effect of certain soils on the colours of
the petals. In garden-mould or compost, the flowers are in-
variably red ; in some kinds of bog-earth they are blue ; and
the same change is always produced by a particular sort of
yellow loam.

Linnaeus was of opinion that the primrose, oxlip, cowslip,
and polyanthus, were only varieties of the same species. The
majority of modern botanists, on the contrary, consider them
to be distinct, although some conceived that the oxlip might
be a cross between the cowslip ^nd the primrose. Mr. Her-
bert has lately recorded the following experiment:—" I raised
from the natural seed of one umbel of a highly-manured red
cowslip, a primrose, a cowslip, oxlips of the usual and other
colours, a black polyanthus, a hose-in-hose cowslip, and a na-
tural primrose bearing its flower on a polyanthus stalk. From
the seed of that very hose-in-hose cowslip I have since raised a
hose-in-hose primrose. I therefore consider all these to be
only local varieties depending upon soil and situation *." Pro-

* Hort. Trans., vol. iv., p. 19.

Ch. II.]

PRODUCED BY HORTICULTURE.

fessor Henslow, of Cambridge, has since confirmed this experi-
ment of Mr. Herbert, so that we have an example, not only
of the remarkable varieties which the florist can obtain from a
common stock, but of the distinctness of analogous races found
in a wild state *.

On what particular ingredient, or quality in the earth, these
changes depend, has not yet been ascertained^. But garden-
ers are well aware that particular plants, when placed under
the influence of certain circumstances, are changed in various
ways according to the species ; and as often as the experiments
are repeated similar results are obtained. The nature of these
results, however, depends upon the species, and they are, there-
fore, part of the specific character ; they exhibit the same
phenomena again and again, and indicate certain fixed and
invariable relations between the physiological peculiarities of
the plant, and the influence of certain external agents. They
afford no ground for questioning the instability of species, but
rather the contrary ; they present us with a class of pheno-
mena which, when they are more thoroughly understood,
may afford some of the best tests for identifying species, and
proving that the attributes originally conferred, endure so long
as any issue of the original stock remains upon the earth.

* Loudon's Mag. of Nat. Hist., Sept. 1830, vol. iii., p. 408.
f Hort. Trans., vol. iii., p. 173.

I) 2

CHAPTER III.

Variability of a species compared to that of an individual— Species which are
susceptible of modification may be altered greatly in a short time, and in a
few generations ; after which they remain stationary — The animals now subject
to man had originally an aptitude to domesticity — Acquired peculiarities
which become hereditary have a close connexion with the habits or instincts of
the species in a wild state — Some qualities in certain animals have been
conferred with a view of their relation to man — Wild elephant domesticated
in a few years, but its faculties ineapable of further development.

We endeavoured in the last chapter to show, that a belief in
the reality of species is not inconsistent with the idea of a
considerable degree of variability in the specific character.
This opinion, indeed, is little more than an extension of the
idea which we must entertain of the identity of an individual,
throughout the changes which it is capable of undergoing.

If a quadruped, inhabiting a cold northern latitude, and
covered with a warm coat of hair or wool, be transported to a
southern climate, it will often, in the course of a few years, shed
a considerable portion of its coat, which it gradually recovers
on being again restored to its native country. Even there the
same changes are, perhaps, superinduced to a certain extent
by the returns of winter and summer. We know that the
Alpine hare* and the ermine f become white during winter, and
again obtain their full colour during the warmer season ; that
the plumage of the ptarmigan undergoes a like metamorphosis
in colour and quantity, and that the change is equally tem-
porary. We are aware that, if we reclaim some wild animal,
and modify its habits and instincts by domestication, it may,
if it escapes, become in a few years- nearly as wild and untrac-
tableas ever; and if the same individual be again retaken, it
may be reduced to its former tame state. A plant is placed
in a prepared soil in order that the petals of its flowers may
multiply, and their colour be heightened or changed ; if we

* Lepus variabilis.— Pallas, -J- Mustek erminea.— Linn.

Ch. III.]

EXTENT OF CHANGE IN SPECIES.

en withhold our care, the flowers of this same individual
become again single. In these, and innumerable other instances,
we must suppose that the individual was produced with a
certain number of qualities; and, in the case of animals, with a
variety of instincts, some of which may or may not be
developed according to circumstances, or which, after having
been called forth, may again become latent when the exciting
causes are removed.

Now the formation of races seems the necessary consequence
of such a capability in individuals to vary, if it be a general
law that the offspring should very closely resemble the
parent. But, before we can infer that there are no limits to
the deviation from an original type which may be brought
about in the course of an indefinite number of generations, we
ought to have some proof that, in each successive generation,
individuals may go on acquiring an equal amount of new
peculiarities, under the influence of equal changes of circum-
stances. The balance of evidence, however, inclines most
decidedly on the opposite side, for in all cases we find that the
quantity of divergence diminishes from the first in a very
rapid ratio.

It cannot be objected, that it is out of our power to go on
varying the circumstances in the same manner as might happen
in the natural course of events during; some great geological
cycle. For in the first place, where a capacity is given to
individuals to adapt themselves to new circumstances, it does
not generally require a very long period for its development ;
if, indeed, such were the case, it is not easy to see how the
modification would answer the ends proposed, for all the
individuals would die before new qualities, habits, or instincts,
were conferred.

Wh en we have succeeded in naturalizing some tropical plant
in a temperate climate, nothing prevents us from attempting gra-
dually to extend its distribution to higher latitudes, or to greater
elevations above the level of the sea, allowing equal quan-
tities of time, or an equal number of generations for habitu-

EXTENT OF CHANGE IN SPECIES.

[Ch. III.

ating the species to successive increments of cold. But every
husbandman and gardener is aware that such experiments will
fail ; and we are more likely to succeed in making some plants,
in the course of the first two generations, support a considerable
degree of difference of temperature than a very small difference
afterwards, though we persevere for many centuries.

It is the same if we take any other cause instead of tem-
perature; such as the quality of the food, or the kind of
dangers to which an animal is exposed, or the soil in which a
plant lives. The alteration in habits, form, or organization, is
often rapid during a short period ; but when the circumstances
are made to vary further, though in ever so slight a degree, all
modification ceases, and the individual perishes. Thus some
herbivorous quadrupeds may be made to feed partially on fish
or flesh, but even these can never be taught to live on some herbs
which they reject, and which would even poison them, although
the same may be very nutritious to other species of the same
natural order. So when man uses force or stratagem against
wild animals, the persecuted race soon becomes more cautious,
watchful, and cunning; new instincts seem often to be deve-
loped, and to become hereditary in the first two or three
generations; but let the skill and address of man increase,
however gradually, no further variation can take place, no new
qualities are elicited by the increasing dangers. The alter-
ation of the habits of the species has reached a point beyond
which no ulterior modification .is possible, however indefinite
the lapse of ages during which the new circumstances operate.
Extirpation then follows, rather than such a transformation as
could alone enable the species to perpetuate itself under the
new state of things.

It has been well observed by M. F. Cuvier and M. Dureau
de la Malle, that unless some animals had manifested in a wild
state an aptitude to second the efforts of man, their domesti-
cation would never have been attempted. If they had all
resembled the wolf, the fox, and the hyaena, the patience of
the experimentalist would have been exhausted by innumer-

Ch. III.]

ACQUIRED INSTINCTS HEREDITARY .

able failures before he at last succeeded in obtaining some
imperfect results ; so, if the first advantages derived from the
cultivation of plants had been elicited by as tedious and costly
a process as that by which we now make some slight addi-
tional improvement in certain races, we should have remained
to this day in ignorance of the greater number of their useful
qualities.

It is undoubtedly true, that many new habits and qualities
have not only been acquired in recent times by certain races of
dogs, but have been transmitted to their offspring. But in these
cases it will be observed, that the new peculiarities have an inti-
mate relation to the habits of the animal in a wild state, and
therefore do not attest any tendency to departure to an indefi-
nite extent from the original type of the species. A race of
dogs employed for hunting deer in the platform of Santa Fe
in Mexico, affords a beautiful illustration of a new hereditary
instinct. The mode of attack, observes M. Roulin, which
they employ, consists in seizing the animal by the belly and
overturning it by a sudden effort, taking advantage of the
moment when the body of the deer rests only upon the fore-
legs. The weight of the animal thus thrown over,, is often six
times that of its antagonist. The dog of pure breed inherits a
disposition to this kind of chase, and never attacks a deer from
before while running. Even should the latter, not perceiving
him, come directly upon him, the dog steps aside and makes his
assault on the flank, whereas other hunting dogs, though of
superior strength and general sagacity, which are brought from
Europe, are destitute of this instinct. For want of similar
precautions, they are often killed by the deer on the spot, the
vertebras of their neck being dislocated by the violence of the
shock *.

A new instinct also has become hereditary in a mongrel race
of dogs employed by the inhabitants of the banks of the Mag-
dalen a, almost excusively in hunting the white-lipped pecari.
The address of these dogs consists in restraining their ardour,,

* M. Roulin, Ann. des Sci. Nat., torn, xvi. p. 16, 1829.

ACQUIRED INSTINCTS HEREDITARY.

[Ch. III.

and attaching themselves to no animal in particular, but keep-
ing the whole herd in check. Now, among these dogs some
are found, which, the very first time they are taken to the
woods, are acquainted with this mode of attack ; whereas, a
dog of another breed starts forward at once, is surrounded
by the pecari, and whatever may be his strength is destroyed
in a moment.

Some of our countrymen, engaged of late in conducting the
principal mining association in Mexico * carried out with them
some English greyhounds of the best breed, to hunt the hares
which abound in that country. The great platform which is the
scene of sport is at an elevation of about nine thousand feet
above the level of the sea, and the mercury in the barometer
stands habitually at the height of about nineteen inches. It
was found that the greyhounds could not support the fatigues
of a long chase in this attenuated atmosphere, and before they
could come up with their prey, they lay down gasping for
breath ; but these same animals have produced whelps which
have grown up, and are not in the least degree incommoded by
the want of density in the air, but run down the hares with as
much ease as the fleetest of their race in this country.

The fixed and deliberate stand of the pointer has with
propriety been regarded as a mere modification of a habit,
which may have been useful to a wild race accustomed to
wind game, and steal upon it by surprise, first pausing for
an instant in order to spring with unerring aim. The faculty
of the Retriever, however, may justly be regarded as more
inexplicable and less easily referrible to the instinctive passions
of the species. M. Majendie, says a French writer in a
recently-published memoir, having learnt that there was a race
of dogs in England, which stopped and brought back game of
their own accord, procured a pair, and having obtained a whelp
from them kept it constantly under his eyes, until he had an
opportunity of assuring himself that, without having received any
instruction and on the very first day that it was carried to the
* The Real del Monte Company.

Ch. HI.]

INFLUENCE OF DOMESTICATION.

chase, it brought back game with as much steadiness as dogs
which had been schooled into the same manoeuvre by means
of the whip and collar.

Such attainments, as well as the habits and dispositions
which the shepherd's dog and many others inherit, seem to be
of a nature and extent which we can hardly explain by sup-
posing them to be modifications of instincts necessary for the
preservation of the species in a wild state. When such remark-
able habits appear in races of this species, we may reasonably
conjecture that they were given with no other view than for
the use of man and the preservation of the dog which thus
obtains protection.

As a general rule, we fully agree with M. F. Cuvier that, in
studying the habits of animals, we must attempt, as far as pos-
sible, to refer their domestic qualities to modifications of instincts
which are implanted in them in a state of nature ; and that writer
has successfully pointed out, in an admirable essay on the
domestication of the mammalia, the true origin of many dispo-
sitions which are vulgarly attributed to the influence of education
alone*. But we should go too far if we did not admit that some
of the qualities of particular animals and plants may have been
given solely with a view to the connexion which it was foreseen
would exist between them and man — especially when we see
that connexion to be in many cases so intimate, that the
greater number, and sometimes all the individuals of the
species which exist on the earth are in subjection to the human
race.

We can perceive in a multitude of animals, especially in
some of the parasitic tribes, that certain instincts and organs
are conferred for the purpose of defence or attack against some
other species. Now if we are reluctant to suppose the exist-
ence of similar relations between man and the instincts of many
of the inferior animals, we adopt an hypothesis no less violent,
though in the opposite extreme to that which has led some to
imagine the whole animate and inanimate creation to have been

* Mem. du Mus. d'Hist. Nat.— Jameson, Ed. New Phil. Jouru., Nos. 6, 7, 8.

ACQUIRED

INSTINCTS

HEREDITARY.

[Ch. III.

made solely for the support, gratification, and instruction of
mankind.

Many species most hostile to our persons or property mul-
tiply in spite of our efforts to repress them ; others, on the con-
trary, are intentionally augmented many hundred-fold in
number by our exertions. In such instances we must imagine
the relative resources of man and of species, friendly or
inimical to him, to have been prospectively calculated and
adjusted. To withhold assent to this supposition would be to
refuse what we must grant in respect to the economy of Nature
in every other part of the organic creation ; for the various
species of contemporary plants and animals have obviously
their relative forces nicely balanced, and their respective tastes,
passions, and instincts, so contrived, that they are all in perfect
harmony with each other. In no other manner could it
happen, that each species surrounded as it is by countless
dangers should be enabled to maintain its ground for periods
of considerable duration.

The docility of the individuals of some of our domestic
species extending, as it does, to attainments foreign to their
natural habits and faculties., may perhaps have been conferred
with a view to their association with man. But lest species
should be thereby made to vary indefinitely, we find that such
habits are never transmissible by generation.

A pig has been trained to hunt and point game with great
activity and steadiness * ; and other learned individuals, of the
same species, have been taught to spell ; but such fortuitous
acquirements never become hereditary, for they have no rela-
tion whatever to the exigencies of the animal in a wild state,
and cannot therefore be developments of any instinctive propen-
sities.

An animal in domesticity, says M. F. Cuvier, is not essen-
tially in a different situation in regard to the feeling of
restraint from one left to itself. It lives in society without

* In the New Forest, near Ringwood, Hants, by Mr. Toomer, keeper of Broomy
Lodge.

Ch. III.]

INFLUENCE OF DOMESTICATION.

constraint, because without doubt it was a social animal, and it
conforms itself to the will of man, because it had a chief to
which in a wild state it would have yielded obedience. There
is nothing in its new situation that is not, conformable to its
propensities ; it is satisfying its wants by submission to a
master, and makes no sacrifice of its natural inclinations. All
the social animals when left to themselves form herds more or
less numerous, and all the individuals of the same herd know
each other,, are mutually attached, and will not allow a strange
individual to join them. In a wild state, moreover, they obey
some individual, which by its superiority has become the chief
of the herd. Oar domestic species had originally this sociabi-
lity of disposition, and no solitary species, however easy it
may be to tame it, has yet afforded true domestic races. We
merely, therefore, develope to our own advantage, propensities
which propel the individuals of certain species to draw near to
their fellows.

The sheep which we have reared is induced to follow us, as
it would be led to follow the flock among which it was
brought up ; and when individuals of gregarious species have
been accustomed to one master, it is he alone whom they
acknowledge as their chief, he only whom they obey. — " The
elephant only allows himself to be led by the carnac whom he
has adopted ; the dog itself, reared in solitude with its master,
manifests a hostile disposition towards all others; and every-
body knows how dangerous it is to be in the midst of a herd of
cows, in pasturages that are little frequented, when they have
not at their head the keeper who takes care of them."

" Everything, therefore, tends to convince us, that formerly
men were only, with regard to the domestic animals, what those
who are particularly charged with the care of them still are,
namely, members of the society, which these animals form among
themselves, and that they are only distinguished in the general
mass by the authority which they have been enabled to assume
from their superiority of intellect. Thus, every social animal
which recognizes man as a member, and as the chief of its

MODIFICATIONS OF INSTINCTS

[Ch. IIL

herd, is a domestic animal. It might even be said that from
the moment when such an animal admits man as a member of
its society, it is domesticated, as man could not enter into such
a society without becoming the chief of it *."

But the ingenious author whose observations we have here
cited, admits that the obedience which the individuals of many
domestic species yield indifferently to every person is without
analogy in any state of things which could exist previously
to their subjugation by man. Each troop of wild horses, it is
true, has some stallion for its chief, who draws after him all
the individuals of which the herd is composed ; but when a
domesticated horse has passed from hand to hand, and has
served several masters, he becomes equally docile towards any
person, and is subjected to the whole human race. It seems
fair to presume, that the capability in the instinct of the horse
to be thus modified, was given to enable the species to render
greater services to man ; and, perhaps, the facility with which
many other acquired characters become hereditary in various
races of the horse, may be explicable only on a like supposition.
The amble, for example, a pace to which the domestic races
in Spanish America are exclusively trained, has, in the course
of several generations, become hereditary, and is assumed by
all the young colts before they are broken in %

It seems also reasonable to conclude, that the power be-
stowed on the horse, the dog, the ox, the sheep, the cat, and
many species of domestic fowls, of supporting almost every
climate, was given expressly to enable them to follow man
throughout all parts of the globe — in order that we might
obtain their services, and they our protection. If it be objected
that the elephant, which, by the union of strength, intelligence,
and docility, can render the greatest services to mankind, is
incapable of living in any but the warmest latitudes, we may
observe, that the quantity of vegetable food required by this

* Mem. da Mus. d'Hist. Nat.
f Bureau de la Malle, Ann. des Sci. Nat., torn. xxj. p. 58.

&u in.]

PRODUCED BY DOMESTICATION.

quadruped would render its maintenance, in the temperate
zone, too costly, and in the arctic impossible.

Among the changes superinduced by man, none appear, at
first sight, more remarkable than the perfect tameness of cer-
tain domestic races. It is well known, that at however early
an age we obtain possession of the young of many unreclaimed
races, they will retain^ throughout life, a considerable timidity
and apprehensiveness of danger; whereas, after one or two
generations, the descendants of the same will habitually place
the most implicit confidence in man. There is good reason,
however, to suspect that such changes are not without analogy
in a state of nature, or, to speak more correctly, in situations
where man has not interfered.

Thus Dr. Richardson informs us, in his able history of the
habits of North American animals, that t( in the retired parts
of the mountains, where the hunters had seldom penetrated,
there is no difficulty in approaching the Hocky Mountain sheep,
which there exhibit the simplicity of character so remarkable
in the domestic species; but where they have been often fired
at, they are exceedingly wild, alarm their companions, on the
approach of danger, by a hissing noise, and scale the rocks
with a speed and agility that baffles pursuit

It is probable, therefore, that as man, in diffusing himself
over the globe, has tamed many wild races, so also he has made
many tame races wild. Had some of the larger carnivorous
beasts, capable of scaling the rocks, made their way into the
North American mountains before our hunters, a similar alte-
ration in the instincts of the sheep would doubtless have been
brought about.

No animal affords a more striking illustration of the prin-
cipal points we have been endeavouring to establish than the
elephant. For in the first place, the wonderful sagacity with
which he accommodates himself to the society of man, and the
new habits which he contracts are not the result of time nor
of modifications produced in the course of many generations,

* Fauna Boreali-Americana, page 273.

MODIFICATIONS OF INSTINCTS

[Ch. III.

These animals will breed in captivity, as is now ascertained in
opposition to the vulgar opinion of many modern naturalists,
and in conformity to that of the ancients iElian and Columella*.
Yet it has always been the custom, as the least expensive mode
of obtaining them, to capture wild individuals in the forests,
usually when full grown, and in a few years after they are
taken, sometimes, it is said, in the space of a few months, their
education is completed.

Had the whole species been domesticated from an early
period in the history of man, like the camel, their superior
intelligence would doubtless have been attributed to their
long and familiar intercourse with the lord of the creation :
but we know that a few years is sufficient to bring about this
wonderful change of habits ; and, although the same individual
may continue to receive tuition for a century afterwards, yet
it makes no further progress in the general development of
its faculties. Were it otherwise, indeed, the animal would
soon deserve more than the poet's epithet of " half-reason-
ing."

From the authority of our countrymen employed in the
late Burmese war, it appears, in corroboration of older ac-
countSj that when elephants are required to execute extraor-
dinary tasks, they may be made to understand that they will
receive unusual rewards. Some favourite dainty is shown
to them, in the hope of acquiring which, the work is done.
And so perfectly does the nature of the contract appear to be
understood, that the breach of it, on the part of the master, is
often attended with danger. In this case, a power has been
given to the species to adapt their social instincts to new cir-
cumstances with surprising rapidity ; but the extent of this
change is defined by strict and arbitrary limits. There is no
indication of a tendency to continued divergence from certain
attributes with which the elephant was originally endued, no
ground whatever for anticipating, that in thousands of cen-
turies any material alteration could ever be effected. All that

* Mr, Corse on the Habits, &c, of the Elephant, Phil. Trans. 1799.

Ch. III.]

PRODUCED BY DOMESTICATION.

we can infer from analogy is, that some useful and peculiar
races might probably be formed, if the experiment were fairly
tried, and that some individual characteristic, now only casual
and temporary, might be perpetuated by generation.

In all cases, therefore, where the domestic qualities exist in
animals, they seem to require no lengthened process for their
development, and they appear to have been wholly denied to
some classes, which from their strength and social nature might
have rendered great services to man ; as, for example, the greater
part of the quadrumana. The orang-outang, indeed, which for
its resemblance in form to man, and apparently for no other good
reason, has been assumed, by Lamarck, to be the most perfect
of the inferior animals, has been tamed by the savages of Bor-
neo, and made to climb lofty trees, and to bring down the
fruit. But he is said to yield to his masters an unwilling-
obedience, and to be held in subjection only by severe dis-
cipline. We know nothing of the faculties of this animal
which can suggest the idea that it rivals the elephant in intel-
ligence, much less anything which can countenance the dreams of
those who have fancied that it might have been transmuted into
<e the dominant race." One of the baboons of Sumatra (Simia
carpolegus) appears to be more docile, and is frequently trained
by the inhabitants to ascend trees for the purpose of gathering
cocoa-nuts, a service in which the animal is very expert. He
selects, says Sir Stamford Raffles, the ripe nuts with great judg-
ment, and pulls no more than he is ordered *. The capuchin and
cacajao monkeys are, according to Humboldt, taught to ascend
trees in the same manner, and to throw down fruit on the
banks of the lower Orinoco f.

We leave it to the Lamarckians to explain, how it happens
that those same savages of Borneo have not themselves acquired,
by dint of longing for many generations for the power of climb-
ing trees, the elongated arms of the orang, or even the prehen-

* Linn. Trans, vol. xiii. p. 244.
f Pers. Narr. of Travels to the Equinoctial Regions of the New Continent, in
the years 1799-1804.

; 48

RECAPITULATION.

[Ch. III.

sile tails of some American monkeys. Instead of being
reduced to the necessity of subjugating stubborn and untract-
able brutes, we should naturally have anticipated " that their
wants would have excited them to efforts, and that continued
efforts would have given rise to new organs j" or, rather, to the
re-acquisition of organs which, in a manner irreconcileable
with the princijole of the progressive system, have grown
'obsolete in tribes of men which have such constant need of
•them.

It follows, then, from the different facts which we have con-
sidered in this chapter, that a short period of time is generally
sufficient to effect nearly the whole change which an alteration
of external circumstances can bring about in the habits of a
species, and that such capacity of accommodation to new cir-
cumstances is enjoyed in very different degrees by different
•species.

Certain qualities appear to be bestowed exclusively with a
view to the relations which are destined to exist between dif-
ferent species, and, among others, between certain species and
man ; but these latter are always so nearly connected with the
"original habits and propensities of each species in a wild state,
that they imply no indefinite capacity of varying from the ori-
ginal type. The acquired habits, derived from human tuition,
are rarely transmitted to the offspring ; and when this happens,
it is almost universally the case with those merely which have
some obvious connexion with the attributes of the species
when in a state of independence.

CHAPTER IV.

Consideration of the question whether species have a real existence in nature,
continued — Phenomena of hybrids — Hunter's opinions as to mule animals — i
Mules not strictly intermediate between the parent species — Hybrid plants —
Experiments of Kolreuter — The same repeated by Wiegmann — Vegetable
hybrids prolific throughout several generations — Why so rare in a wild state — «
Decandolle's opinion respecting hybrid plants — The phenomena of hybrids
confirms the doctrine of the permanent distinctness of species — Theory of the
gradation in the intelligence of animals as indicated by the facial angle — Dis-
covery of Tieddemann that the brain of the foetus in mammalia assumes succes-
sively the form of the brain of a fish, reptile, and bird — Bearing of this discovery
on the theory of progressive development and transmutation — Recapitulation.

We have yet to consider another class of phenomena, those
relating to the production of hybrids, which have been regarded
in a very different light with reference to their bearing on the
question of the permanent distinctness of species ; some natu-
ralists considering them as affording the strongest of all proofs
in favour of the reality of species ; others, on the contrary,
appealing to them as countenancing the opposite doctrine, that
all the varieties of organization and instinct now exhibited in
the animal and vegetable kingdoms, may have been propagated
from a small number of original types.

In regard to the mammifers and birds, it is found that no
sexual union will take place between races which are remote
from each other in their habits and organization ; and it is only
in species that are very nearly allied that such unions produce
offspring. It may be laid down as a general rule, admitting
of very few exceptions among quadrupeds, that the hybrid
progeny is steril, and there seem to be no well-authenticated
examples of the continuance of the mule race beyond one gene-
ration. The principal number of observations and experiments
relate to the mixed offspring of the horse and the ass ; and in
this case it is well established, that the male-mule can generate

and the female-mule produce. Such cases occur in Spain and
Vol. II. E

EXPERIMENTS ON

[Ch. IV.

Italy, and much more frequently in the West Indies and New-
Holland ; but these mules have never bred in cold climates,
seldom in warm regions, and still more rarely in temperate
countries.

The hybrid offspring of the female-ass and the stallion, the
•ytvvof of Aristotle, and the hinnus of Pliny 5 differs from the
mule, or the offspring of the ass and mare. In both cases,
says Buffon, these animals retain more of the mother than of
the father, not only in the magnitude but in the figure of the
body ; whereas, in the form of the head^ limbs, and tail, they
bear a greater resemblance to the father. The same naturalist
infers, from various experiments respecting cross-breeds be-
tween the he-goat and ewe, the dog and she -wolf, the goldfinch
and canary-bird, that the male transmits his sex to the greatest
number, and that the preponderance of males over females
exceeds that which prevails where the parents are of the same
species.

The celebrated John Hunter has observed, that the true dis-
tinction of species must ultimately be gathered from their
incapacity of propagating with each other, and producing
offspring capable of again continuing itself. He was unwilling,
however, to admit, that the horse and the ass were of the same
species, because some rare instances had been adduced of the
breeding of mules, which he attributed to a degree of mon-
strosity in the organs of the mule, for these he suggested might
not have been those of a mixed animal, but those of the mare
or female-ass. " This, he argues, is not a far-fetched idea, for
true species produce monsters, and many animals of distinct
sex are incapable of breeding at all; and as we find nature,
in its greatest perfection, deviating from general principles,
why may it not happen likewise in the production of mules, so
that sometimes a mule shall breed from the circumstance of its
being a monster respecting mules ?"

Yet, in the same memoir, this great anatomist inferred that
the wolf, the dog, and the jackal, were all of one species,
because he had found, by two experiments, that the dog would

Ch. IV.]

HYBRID ANIMALS.

breed, both with the wolf and the jackal ; and that the mule,
in each case, would breed again with the dog. In these cases,
however, we may observe, that there was always one parent at
least of pure breed, and no proof was obtained that a true
hybrid race could be perpetuated ; a fact of which we believe
no examples are yet recorded, either in regard to mixtures of
the horse and ass, or any other of the mammalia.

Should the fact be hereafter ascertained, that two mules
can propagate their kind, we must still inquire whether the
offspring may not be regarded in the light of a monstrous
birth, proceeding from some accidental cause, or rather, to
speak more philosophically, from some general law not yet
understood, but which may not be permitted permanently to
interfere with those laws of generation, whereby species may, in
general, be prevented from becoming blended. If, for exam-
ple, we discovered that the progeny of a mule race degenerated
greatly in the first generation, in force, sagacity, or any attri-
bute necessary for its preservation in a state of nature, we
might infer that, like a monster, it is a mere temporary and
fortuitous variety. Nor does it seem probable that the greater
number of such monsters could ever occur unless obtained by
art ; for in Hunter's experiments, stratagem or force was, in
most instances, employed to bring about the irregular con-
nexion *i

It seems rarely to happen that the mule offspring is truly
intermediate in character between the two parents. Thus
Hunter mentions, that, in his experiments, one of the hybrid
pups resembled the wolf much more than the rest of the litter ;
and we are informed by Wiegmann, that in a litter lately
obtained in the Royal Menagerie at Berlin, from a white
pointer and a she-wolf, two of the cubs resembled the common
wolf-dog, but the third was like a pointer with hanging ears.

There is, undoubtedly, a very close analogy between these
phenomena and those presented by the intermixture of distinct
races of the same species, both in the inferior animals and in

* Phil. Trans. 1787. Additional Remarks, Phil. Trans. 1789.

E 2

EXPERIMENTS ON

[Ch. IV.

man. Dr. Prichard, in his " Physical History of Mankind,"
cites examples where the peculiarities of the parents have been
transmitted very unequally to the offspring ; as where children,
entirely white, or perfectly black, have sprung from the
union of the European and the negro. Sometimes the colour,
or other peculiarities of one parent, after having failed to show
themselves in the immediate progeny, reappear in a subsequent
generation, as where a white child is born of two black parents,
the grandfather having been a white *.

The same author judiciously observes, that if different
species mixed their breed, and hybrid races were often propa-
gated, the animal world would soon present a scene of con-
fusion ; its tribes would be everywhere blended together, and
we should, perhaps, find more hybrid creatures than genuine
and uncorrupted races j\

The history of the vegetable kingdom has been thought to
afford more decisive evidence in favour of the theory of the for-
mation of new and permanent species from hybrid stocks. The
first accurate experiments in illustration of this curious subject
appear to have been made by Kolreuter, who obtained a hybrid
from two species of Tobacco, Nicotiana rustica and N. panicu-
lata, which differ greatly in the shape of their leaves, the colour of
the corolla, and the height of the stem. The stigma of a female
plant of N. rustica was impregnated with the pollen of a male
plant of N. paniculata. The seed ripened and produced a hybrid
which was intermediate between the two parents, and which,
like all the hybrids which this botanist brought up, had im-
perfect stamens. He afterwards impregnated this hybrid with
the pollen of N. paniculata, and obtained plants which much
more resembled the last. This he continued through several
generations, until, by due perseverance, he actually changed
the Nicotiana rustica into the Nicotiana paniculata.

The plan of impregnation adopted, was the cutting off of the
anthers of the plant intended for fructification before they had

* Vol.i.,p. 217.

f Ibid., vol. i., p. 97.

Ch. IV.] HYBRID PLANTS. 55

shed pollen, and then laying on foreign pollen upon the stigma.
The same experiment has since been repeated, with success,
by Wiegmann, who found that he could bring back the hybrids
to the exact likeness of either parent, by crossing them a suf-
ficient number of times.

The blending of the characters of the parent stocks, in many
other of Weigmann's experiments, was complete ; the colour
and shape of the leaves and flowers, and even the scent, being
intermediate, as in the offspring of the two species of verbascum.
An intermarriage, also, between the common onion and the leek
(Allium cepa and A, porrum) gave a mule plant, which, in the
character of its leaves and flowers, approached most nearly to
the garden onion, but had the elongated bulbous root and smell
of the leek.

The same botanist remarks, that vegetable hybrids, when not
strictly intermediate, more frequently approach the female than
the male parent species, but they never exhibit characters
foreign to both. A re-cross with one of the original stocks,
generally causes the mule plant to revert towards that stock ;
but this is not always the case, the offspring sometimes con-
tinuing to exhibit the character of a full hybrid.

In general, the success attending the production and per-
petuity of hybrids among plants, depends., as in the animal king-
dom, on the degree of proximity between the species intermarried.
If their organization be very remote, impregnation never takes
place ; if somewhat less distant, seeds are formed, but always
imperfect and steril. The next degree of relationship yields
hybrid seedlings, but these are barren ; and it is only when the
parent species are very nearly allied, that the hybrid race may
be perpetuated for several generations. Even in this case the
best authenticated examples seem confined to the crossing of
hybrids with individuals of pure breed. In none of the expe-
riments most accurately detailed does it appear that both the
parents were mules.

Wiegmann diversified, as much as possible, his mode of
bringing about these irregular unions among plants. He often

RARITY OF HYBRIDS AMONG

[Ch. IV.

sowed parallel rows, near to each other, of the species] from
which he desired to breed, and instead of mutilating, after
Kolreuter's fashion, the plants of one of the parent stocks, he
merely washed the pollen off their anthers. The branches of
the plants, in each row, were then gently bent towards each
other and intertwined, so that the wind, and numerous insects
as they passed from the flowers of one to those of the other
species, carried the pollen and produced fecundation,

The same observer saw a good exemplification of the manner
in which hybrids may be formed in a state of nature. Some
wallflowers and pinks had been growing in a garden, in a dry
sunny situation, and their stigmas had been ripened so as to be
moist, and to absorb pollen with avidity, although their anthers
were not yet developed. These stigmas became impregnated
by pollen, blown from some other adjacent plants of the same
species, but had they been of different species, and not too
remote in their organization, mule races must have resulted.

When, indeed, we consider how busily some insects have been
shown to be engaged in conveying anther-dust from flower to
flower, especially bees, flower-eating beetles, and the like, it
seems a most enigmatical problem how it can happen, that pro-
miscuous alliances between distinct species are not perpetually
occurring.

How continually do we observe the bees diligently employed
in collecting the red and yellow powder by which the stamens of
flowers are covered, loading it on their hind legs, and carrying
it to their hive for the purpose of feeding their young ! In thus
providing for their own progeny,, these insects assist materially
the process of fructification *. Few of our readers need be
reminded, that the stamens in certain plants grow on different
blossoms from the pistils, and unless the summit of the pistil
be touched with the fertilizing dust, the fruit does not swell,
nor the seed arrive at maturity. It is by the help of bees
chiefly, that the development of the fruit of many such species

* See Barton on the Geography of Plants, p. 67.

Ch. IV.]

PLANTS IN A WILD STATE.

is secured, the powder which they have collected from the
stamens being unconsciously left by them in visiting the pistils.

How often, during the heat of a summer's day, do we see
the males of dioecious plants, such as the yew-tree, standing-
separate from the females, and sending off into the air, upon
the slightest breath of wind, clouds of buoyant pollen ! That
the zephyr should so rarely intervene to fecundate the plants
of one species with the anther-dust of others, seems almost to
realize the converse of the miracle believed by die credulous
herdsmen of the Lusitanian mares —

Ore omnes versse in Zephyrum, stant rupibus altis,
Exceptantque leves auras : et ssepe sine ullis
Conjugiis, vento gravidse, mirabile dictu*.

But, in the first place, it appears that there is a natural
aversion in plants, as well as in animals, to irregular sexual
unions ; and in most of the successful experiments in the animal
and vegetable world, some violence has been used, in order to
procure impregnation. The stigma imbibes, slowly and reluc-
tantly, the granules of the pollen of another species, even when
it is abundantly covered with it ; and if it happen that, during
this period, ever so slight a quantity of the anther-dust of its
own species alight upon it, this is instantly absorbed, and the
effect of the foreign pollen destroyed. Besides, it does not often
happen that the male and female organs of fructification, in
different species,, arrive at a state of maturity at precisely the
same time. Even where such synchronism does prevail, so that
a cross impregnation is effected, the chances are very numerous
against the establishment of a hybrid race.

If we consider the vegetable kingdom generally, it must be
recollected, that even of the seeds which are well ripened, the
greater part are either eaten by insects, birds, and other animals,
or decay for want of room and opportunity to germinate. Un-
healthy plants are the first which are cut off by causes prejudicial
to the species, being usually stifled by more vigorous individuals
of their own kind. If, therefore, the relative fecundity or

* Georg. lib. iii. 273.

RARITY OF HYBRIDS AMONG

[Ch. IV.

hardiness of hybrids be in the least degree inferior, they cannot
maintain their footing for many generations, even if they were
ever produced beyond one generation in a wild state. In the
universal struggle for existence, the right of the strongest
eventually prevails ; and the strength and durability of a race
depends mainly on its prolificness, in which hybrids are
acknowledged to be deficient.

Centaur ea hyhrida, a plant which never bears seed, and is
supposed to be produced by the frequent intermixture of two
well-known species of Centaurea, grows wild upon a hill near
Turin. Ranunculus lacerus, also steril, has been produced
accidentally at Grenoble, and near Paris, by the union of two
Ranunculi ; but this occurred in gardens *.

Mr. Herbert, in one of his ingenious papers on mule plants,
endeavours to account for their non-occurrence in a state of
nature, from the circumstance that all the combinations that
were likely to occur, have already been made many centuries
ago, and have formed the various species of botanists ; but in
our gardens, he says, whenever species, having a certain degree of
affinity to each other, are transported from different countries,
and brought for the first time into contact, they give rise to
hybrid species f . But we have no data, as yet, to warrant the
conclusion, that a single permanent hybrid race has ever been
formed, even in gardens,, by the intermarriage of two allied
species brought from distant habitations. Until some fact of
this kind is fairly established, and a new species, capable of
perpetuating itself in a state of perfect independence of man
can be pointed out, we think it reasonable to call in question
entirely this hypothetical source of new species. That varieties
do sometimes spring up from cross breeds^ in a natural way,
can hardly be doubted, but they probably die out even more
rapidly than races propagated by grafts or layers.

Decandolle, whose opinion on a philosophical question of this
kind deserves the greatest attention, has observed, in his Essay

* Hon. and Rev. W. Herbert, Hort. Trans., vol. iv., p. 41.

f Ibid.

Ch. IV.]

PLANTS IN A WILD STATE.

on Botanical Geography, that the varieties of plants range
themselves under two general heads : those produced by exter-
nal circumstances, and those formed by hybridity. After
adducing various arguments to show that neither of these
causes can explain the permanent diversity of plants indigenous
in different regions, he says, in regard to the crossing of races,
" I can perfectly comprehend, without altogether sharing the
opinion, that where many species of the same genera occur near
together, hybi'id species may be formed, and I am aware that
the great number of species of certain genera which are found
in particular regions, may be explained in this manner ; but
I am unable to conceive how any one can regard the same
explanation as applicable to species which live naturally at great
distances. If the three larches, for example, now known in the
world, lived in the same localities, I might then believe that
one of them was the produce of the crossing of the two others;
but I never could admit that the Siberian species has been
produced by the crossing of those of Europe and America. I
see, then, that there exist, in organized beings, permanent dif-
ferences which cannot be referred to any one of the actual
causes of variation^ and these differences are what constitute
species

The most decisive arguments, perhaps, amongst many others,
against the probability of the derivation of permanent species
from cross breeds, are to be drawn from the fact alluded to by
Decandolle, of species having a close affinity to each other
occurring in distinct botanical provinces, or countries in-
habited by groups of distinct species of indigenous plants. For
in this case naturalists, who are not prepared to go the whole
length of the transmutationists, are under the necessity of
admitting, that in some cases species which approach very near
to each other in their characters, were so created from their
origin ; an admission fatal to the idea of its being a general
law of nature^ that a few original types only should be formed,,

* Essai El&nentaire, &c. 3me. partie.

DIFFICULTIES ATTENDING THE

[Ch. IV.

and that all intermediate races should spring from the intermix-
ture of those stocks.

This notion, indeed, is wholly at variance with all that we
know of hybrid generation ; for the phenomena entitle us to
affirm, that had the types been at first somewhat distant, no
cross-breeds voould ever have been produced, much less those
prolific races which we now recognise as distinct species.

In regard, moreover, to the permanent propagation of hybrid
races among animals, insuperable difficulties present themselves,
when we endeavour to conceive the blending together of the
different instincts and propensities of two species, so as to
insure the preservation of the intermediate race. The common
mule, when obtained by human art, may be protected by the
power of man ; but in a wild state, it would neither have pre-
cisely the same wants as the horse or the ass : and if, in con-
sequence of some difference of this kind, it strayed from the
herd, it would soon be hunted down by beasts of prey and
destroyed.

If we take some genus of insects, such as the bee, we
find that each of the numerous species has some difference in its
habits, its mode of collecting honey, or constructing its dwel-
ling, or providing for its young, and other particulars. In
the case of the common hive-bee, the workers are described, by
Kirby and Spence, as being endowed with no less than thirty
distinct instincts*. So also we find that amongst a most
numerous class of spiders, there are nearly as many different
modes of spinning their webs as there are species. When we
recollect how complicated are the relations of these instincts
with co-existing species, both of the animal and vegetable king-
doms, it is scarcely possible to imagine that a bastard race could
spring from the union of two of these species, and retain just
so much of the qualities of each parent-stock as to preserve its
ground in spite of the dangers which surround it.

We should also ask, if a few generic types alone have been
created among insects, and the intermediate species have pro-

* Intr. to Entom., vol. ii., p. 504. Ed. 1817.

Ch. IV.]

PROPAGATION OF HYBRIDS

ceeded from hybridity, where are those original types, com-
bining, as they ought to do, the elements of all the instincts
which have made their appearance in the numerous derivative
races ? So also in regard to animals of all classes, and of plants ;
if species in general are of hybrid origin, where are the stocks
which combine in themselves the habits, properties, and organs,
of which all the intervening species ought to afford us mere
modifications ?

We shall now conclude this subject by summing up, in a
few words, the results to which the consideration of the pheno-
mena of hybrids has led us. It appears that the aversion of
individuals of distinct species to the sexual union is common
to animals and plants, and that it is only when the species
approach near to each other, in their organization and habits,
that any offspring are produced from their connexion. Mules
are of extremely rare occurrence in a state of nature, and no
examples are yet known of their having procreated in a wild
state. But it has been proved, that hybrids are not univer-
sally steril, provided the parent stocks have a near affinity to
each other, although the continuation of the mixed race, for
several generations, appears hitherto to have been obtained
only by crossing the hybrids with individuals of pure species,
an experiment which by no means bears out the hypothesis
that a true hybrid race could ever be permanently established.

Hence we may infer, that aversion to sexual intercourse is,
in general, a good test of the distinctness of original stocks, or
of species, and the procreation of hybrids is a proof of the very
near affinity of species. Perhaps, hereafter, the number of
generations for which hybrids may be continued, before the
race dies out (for it seems usually to degenerate rapidly), may
afford the zoologist and botanist an experimental test of the
difference in the degree of affinity of allied species.

We may also remark, that if it could have been shown that
a single permanent species had ever been produced by hybri-
dity (of which there is no satisfactory proof), it might cer-
tainly have lent some countenance to the notions of the ancients

GRADATION IN INTELLECT AS SHEWN

[Ch. IV.

respecting the gradual deterioration of created things, but none
whatever to Lamarck's theory of their progressive perfectibility ;
for observations have hitherto shown that there is a tendency,
in mule animals and plants, to degenerate in organization.

We have already remarked, that the theory of progressive
development arose from an attempt to ingraft the doctrines of
the transmutationists upon one of the most popular generaliza-
tions in geology. But modern geological researches have almost
destroyed every appearance of that gradation in the successive
groups of animate beings, which was supposed to indicate the
slow progress of the organic world from the more simple to the
more compound structure. In the more modern formations,
we find clear indications that the highest orders of the terres-
trial mammalia were fully represented during several successive
epochs ; but, in the monuments which we have hitherto exa-
mined of more remote eras, in which there are as yet discovered
few fluviatile, and perhaps no lacustrine formations, and, there-
fore, scarcely any means of obtaining an insight into the zoology
of the then existing continents, we have only as yet found one
example of a mammiferous quadruped. The recent origin of
man, and the absence of all signs of any rational being holding
an analogous relation to former states of the animate world,
affords one, and the only reasonable argument, in support of the
hypothesis of a progressive scheme, but none whatever in favour
of the fancied evolution of one species out of another.

When the celebrated anatomist, Camper, first attempted to
estimate the degrees of sagacity of different animals, and of the
races of man, by the measurement of the facial angle, some
speculators were bold enough to affirm, that certain simia? dif-
fered as little from the more savage races of men, as do these
from the human race in general ; and that a scale might be
traced from " apes with foreheads villanous low r ," to the
African variety of the human species, and from that to the
European. The facial angle was measured by drawing a line
from the prominent centre of the forehead to the most advanced
part of the lower jaw-bone, and observing the angle which it

Ch. IV.]

BY THE FACIAL ANGLE.

made with the horizontal line ; and it was affirmed, that there
was a regular series from birds to the mammalia.

The gradation from the dog to the monkey was said to he per-
fect, and from that again to man. One of the ape tribe has a facial
angle of 42°, and another, which approximated nearest to man
in figure, an angle of 50°. To this succeeds (longo sed proximus
intervallo) the head of the African negro, which, as well as that of
the Kalmuc, forms an angle of 70°, while that of the European
contains 80°. The Roman painters preferred the angle of 95°,
and the character of beauty and sublimity, so striking in some
works of Grecian sculpture, as in the head of Apollo, and in
the Medusa of Sisocles, is given by an angle which amounts to
100° *

A great number of valuable facts and curious analogies
in comparative anatomy, were brought to light during the
investigations which were made by Camper, John Hunter, and
others, to illustrate this scale of organization ; and their facts
and generalizations must not be confounded with the fanciful
systems which White and others deduced from them f .

That there is some connexion between an elevated and capa-
cious forehead in certain races of men, and a large development
of the intellectual faculties, seems highly probable; and that a
low facial angle is frequently accompanied with inferiority of
mental powers, is certain ; but the attempt to trace a graduated
scale of intelligence through the different species of animals
accompanying the modifications of the form of the skull, is a
mere visionary speculation. It has been found necessary to
exaggerate the sagacity of the ape tribe at the expense of the
dog, and strange contradictions have arisen in the con-
clusions deduced from the structure of the elephant, some
anatomists being disposed to deny the quadruped the intelli-
gence which he really possesses, because they found that the
volume of his brain was small in comparison to that of the other
mammalia, while others were inclined to magnify extravagantly

* Prichard, Phys. Hist, of Mankind, vol. i., p. 159.
f Ch. White on the regular Gradation in Man, &c, 1799.

TIEDDEMANN ON THE BRAIN OF THE

[Ch. IV.

the superiority of its intellect, because the vertical height of its
skull is so great when compared to its horizontal length.

It would be irrelevant to our subject if we were to enter into
a farther discussion on these topics, because, even if a gradu-
ated scale of organization and intelligence could have been
established, it would prove nothing in favour of a tendency, in
each species, to attain a higher state of perfection. We may
refer the reader to the writings of Blumenbach, Prichard,
Lawrence, and others, for convincing proofs that the varieties
of form, colour, and organization of different races of men, are
perfectly consistent with the generally received opinion, that all
the individuals of the species have originated from a single
pair ; and while they exhibit in man as many diversities of a
physiological nature, as appear in any other species, they con-
firm also the opinion of the slight deviation from a common
standard of which a species is capable.

The power of existing and multiplying in every latitude, and
in every variety of situation and climate, which has enabled
the great human family to extend itself over the habitable globe,
is partly, says Lawrence, the result of physical constitution,
and partly of the mental prerogative of man. If he did not
possess the most enduring and flexible corporeal frame, his
arts would not enable him to be the inhabitant of all climates,
and to brave the extremes of heat and cold, and the other
destructive influences of local situation * Yet, notwithstand-
ing this flexibility of bodily frame, we find no signs of indefinite
departure from a common standard, and the intermarriages of
individuals of the most remote varieties are not less fruitful
than between those of the same tribe.

There is yet another department of anatomical discovery, to
which we must not omit some allusion, because it has appeared
to some persons to afford a distant analogy, at least, to that
progressive development by which some of the inferior species
may have been gradually perfected into those of more complex
organization. Tieddemann found, and his discoveries have been

* Lawrence, Lectures on Phys. Zool. and Nat. Hist, of Man, p. 192. Ed. 1823.

Ch. IV.]

FOETUS IN VERTEBRATED ANIMALS.

most fully confirmed and elucidated by M. Serres, that the
brain of the foetus, in the highest class of vertebrated animals,
assumes, in succession, the various forms which belong to fishes,
reptiles, and birds, before it acquires those additions and modi-
fications which are peculiar to the mammiferous tribe. So that
in the passage from the embryo to the perfect mammifer, there
is a typical representation, as it were, of all those transforma-
tions which the primitive species are supposed to have under-
gone, during a long series of generations, between the present
period and the remotest geological era.

If you examine the brain of the mammalia, says M. Serres,
at an early stage of uterine life, you perceive the cerebral
hemispheres consolidated, as in fish,, in two vesicles isolated one
from the other ; at a later period, you see them affect the con-
figuration of the cerebral hemispheres of reptiles ; still later
again, they present you with the forms of those of birds ; finally,
they acquire, at the era of birth, and sometimes later, the per-
manent forms which the adult mammalia present.

The cerebral hemispheres, then, only arrive at the state
which we observe in the higher animals by a series of succes-
sive metamorphoses. If we reduce the whole of these evolu-
tions to four periods, we shall see that in the first are born the
cerebral lobes of fishes^ and this takes place homogeneously in
all classes. The second period will give us the organization
of reptiles ; the third the brain of birds ; and the fourth the
complex hemispheres of mammalia.

If we could develop the different parts of the brain of the
inferior classes, we should make in succession a reptile out of a
fish, a bird out of a reptile, and a mammiferous quadruped out
of a bird. If, on the contrary, we could starve this organ in
the mammalia, we might reduce it successively to the con-
dition of the brain of the three inferior classes.

Nature often presents us with this last phenomenon in mon-
sters, but never exhibits the first. Among the various defor-
mities which organized beings may experience, they never pass
the limits of their own classes to put on the forms of the class

RECAPITULATION.

[Ch. IV,

above them. Never does a fish elevate itself so as to assume
the form of the brain of a reptile ; nor does the latter ever
attain that of birds ; nor the bird that of the mammifer. It
may happen that a monster may have two heads, but the con-
formation of the brain always remains circumscribed narrowly
within the limits of its class *.

It will be observed, that these curious phenomena disclose,
in a highly interesting manner, the unity of plan that runs
through the organization of the whole series of vertebrated
animals ; but they lend no support whatever to the notion of a
gradual transmutation of one species into another, least of all of
the passage, in the course of many generations, from an animal
of a more simple, to one of a more complex structure. On the
contrary, were it not for the sterility imposed on monsters, as
well as on hybrids in general, the argument to be derived from
Tieddemann's discovery, like that deducible from experiments
respecting hybridity, would be in favour of the successive
degeneracy , rather than the perfectibility, in the course of ages,
of certain classes of organic beings.

For the reasons, therefore, detailed in this and the two pre-
ceding chapters, we draw the following inferences, in regard to
the reality of species in nature.

First, That there is a capacity in all species to accommodate
themselves, to a certain extent, to a change of external circum-
stances, this extent varying greatly according to the species.

2dly. When the cnange of situation which they can endure is
great, it is usually attended by some modifications of the form,
colour, size, structure, or other particulars j *but the mutations
thus superinduced are governed by constant laws, and the capa-
bility of so varying forms part of the permanent specific cha-
racter.

3dly. Some acquired peculiarities of form, structure, and
instinct, are transmissible to the offspring ; but these consist

* E. R. A. Serres, Auatomie Comparee du Cerveau, illustrated by numerous
plates, torn, i., 1824.

Ch. IV.]

RECAPITULATION.

of such qualities and attributes only as are intimately related
to the natural wants and propensities of the species.

4thly. The entire variation from the original type, which
any given kind of change can produce, may usually be effected
in a brief period of time, after which no farther deviation can
be obtained by continuing to alter the circumstances, though
ever so gradually, — indefinite divergence, either in the way of
improvement or deterioration, being prevented, and the least
possible excess beyond the defined limits being fatal to the
existence of the individual.

5thly. The intermixture of distinct species is guarded against
by the aversion of the individuals composing them to sexual
union, or by the sterility of the mule offspring. It does not
appear that true hybrid races have ever been perpetuated for
several generations, even by the assistance of man ; for the
cases usually cited relate to the crossing of mules with indi-
viduals of pure species, and not to the intermixture of hybrid
with hybrid.

6thly. From the above considerations, it appears that species
have a real existence in nature, and that each was endowed, at
the time of its creation, with the attributes and organization by
which it is now distinguished.

Vol. II.

CHAPTER V.

Laws which regulate the geographical distribution of species — Analogy of climate
not attended with identity of species — Botanical geography — Stations — Habi-
tations — Distinct provinces of indigenous plants — Vegetation of islands — »
Marine vegetation — In what manner plants become diffused — Effects of wind,
rivers, marine currents — Agency of animals — Many seeds pass through the
stomachs of animals and birds undigested — Agency of man in the dispersion
of plants, both voluntary and involuntary — Its analogy to that of the inferior
animals.

Next to determining the question whether species have a real
existence, the consideration of the laws which regulate their
geographical distribution is a subject of primary importance
to the geologist. It is only by studying these laws with atten-
tion, by observing the position which groups of species occupy
at present, and inquiring how these may be varied in the course
of time by migrations, by changes in physical geography, and
other causes, that we can hope to learn whether the duration of
species be limited, or in what manner the state of the animate
world is affected by the endless vicissitudes of the inanimate.

That different regions of the globe are inhabited by entirely
distinct animals and plants is a fact which has been familiar to
all naturalists since Buffon first pointed out the want of specific
identity between the land quadrupeds of America and those of
the Old World. The same phenomenon has, in later times,
been forced, in a striking manner, upon our attention, by the
examination of New Holland, where the indigenous species of
animals and plants were found to be, almost without exception,
distinct from those known in other parts of the world.

But the extent of this parcelling out of the globe amongst
different nations, as they have been termed, of plants and ani-
mals, — the universality of a phenomenon so extraordinary and
unexpected, may be considered as one of the most interesting
facts clearly established by the advance of modern science.

Ch. V.]

BOTANICAL GEOGRAPHY.

Scarcely fourteen hundred species of plants appear to have
been known and described by the Greeks, Romans, and
Arabians. At present, more than three thousand species are
enumerated, as natives of our own island *. In other parts of
the world there have been collected, perhaps, upwards of seventy
thousand species. It was not to be supposed, therefore, that
the ancients should have acquired any correct notions respect-
ing what may be called the geography of plants, although the
influence of climate on the character of the vegetation could
hardly have escaped their observation.

Antecedently to investigation, there was no reason for pre-
suming that the vegetable productions, growing wild in the
eastern hemisphere, should be unlike those of the western,
in the same latitude ; nor that the plants of the Cape of Good
Hope should be unlike those of the South of Europe ; situa-
tions where the climate is little dissimilar. The contrary sup-
position would have seemed more probable, and we might have
anticipated an almost perfect identity in the animals and plants
which inhabit corresponding parallels of latitude. The dis-
covery, therefore, that each separate region of the globe, both
of the land and water, is occupied by distinct groups of
species, and that most of the exceptions to this general rule
may be referred to disseminating causes now in operation, is
eminently calculated to excite curiosity, and to stimulate us to
seek some hypothesis respecting the first introduction of species
which may be reconcileable with such phenomena.

A comparison of the plants of different regions of the globe
affords results more to be depended upon in the present state
of our knowledge, than those relating to the animal kingdom,
because the science of botany is more advanced, and probably
comprehends a great proportion of the total number of the
vegetable productions of the whole earth.

Humboldt, in several eloquent passages of his Personal
Narrative, was among the first to promulgate philosophical
views on this subject. Every hemisphere, says this traveller,

* Barton's Lectures on the Geography of Plants, p. 2.

F 2

BOTANICAL GEOGRAPHY.

tCh. V.

produces plants of different species ; and it is not by the
diversity of climates that we can attempt to explain why equi-
noctial Africa has no lauriniae, and the New World no heaths ;
why the calceolarias are found only in the southern hemisphere ;
why the birds of the continent of India glow with colours less
splendid than the birds of the hot parts of America ; finally,
why the tiger is peculiar to Asia, and the ornithorhynchus to
New Holland *;

" We can conceive, he adds, that a small number of the families
of plants, for instance the musacese and the palms, cannot belong
to very cold regions, on account of their internal structure and
the importance of certain organs ; but we cannot explain why
no one of the family of melastomas vegetates north of the
parallel of thirty degrees ; or why no rose-tree belongs to the
southern hemisphere. Analogy of climates is often found in
the two continents without identity of productions f."
[i Tne luminous essay of Decandolle on " Botanical Geogra-
phy" presents us with the fruits of his own researches and
those of Humboldt, Brown, and other eminent botanists, so
arranged, that the principal phenomena of the distribution of
plants are exhibited in connexion with the causes to which
they are chiefly referrible + . " It might not, perhaps, be
difficult," observes this writer, « to find two points, in the
United States and in Europe, or in equinoctial America and
Africa, which present all the same circumstances : as for ex-
ample, the same temperature, the same height above the sea, a
similar soil, an equal dose of humidity, yet nearly all, perhaps
all, the plants in these two similar localities shall be distinct.
A certain degree of analogy, indeed, of aspect, and even of
structure, might very possibly be discoverable between the
plants of the two localities in question, but the species would
in general be different. Circumstances, therefore, different
from those which now determine the stations, have had an
influence on the habitations of plants."

* Pers. Narr., vol. v. p. 180. | IHJ.

* Essai Elementaire de Geographie Botanique. Extrait du 18e vol. du Diet,
des Sci. Nat,

Ch. V.J

STATIONS AND HABITATIONS OF PLANTS.

As we shall frequently have occasion to speak of the stations
and habitations of plants in the technical sense in which the terms
are used in the above passage, we may remind the geological
reader that station indicates the peculiar nature of the locality
where each species is accustomed to grow, and has reference to
climate, soil, humidity, light, elevation above the sea, and other
analogous circumstances ; whereas by habitation is meant a
general indication of the country where a plant grows wild.
Thus the station of a plant may be a salt-marsh, in a temperate
climate, a hill- side, the bed of the sea, or a stagnant pool. Its
habitation may be Europe, North America,, or New Holland
between the tropics. The study of stations has been styled
the topography, that of habitations the geography of botany.
The terms thus defined, express each a distinct class of ideas,
which have been often confounded together, and which are
equally applicable in zoology.

In further illustration of the principle above alluded to, that
difference of longitude, independently of any influence of tem-
perature, is accompanied by a great, and sometimes a complete
diversity in the species of plants, Decandolle observes, that
out of two thousand eight hundred and ninety-one species of
phanerogamic plants described by Pursh, in the United States,
there are only three hundred and eighty-five which are found
in northern or temperate Europe. MM. Humboldt and
Bonpland, in all their travels through equinoctial America,
found only twenty -four species (these being all cyperacea and
graminea) common to America and any part of the Old World.
On comparing New Holland with Europe, Mr. Brown ascer-
tained that out of four thousand one hundred species, dis-
covered in Australia^ there were only one hundred and sixty-
six common to Europe, and of this small number there were
some which may have been transported thither by man. Most
of the others belong to those classes which are provided with
the most ample means of dispersion to vast distances.

But it is still more remarkable, that in the more widely
separated parts of the ancient continent, notwithstanding the

VEGETATION OF ISLANDS.

[Ch. V.

existence of an uninterrupted land communication, the diver-
sity in the specific character of the respective vegetations is
almost as striking. Thus there is found one assemblage of
species in China, another in the countries bordering the Black
Sea and the Caspian, a third in those surrounding the Medi-
terranean, a fourth in the great platforms of Siberia and
Tartary, and so forth.

The distinctness of the groups of indigenous plants, in the
same parallel of latitude, is greatest where continents are dis-
joined by a wide expanse of ocean. In the northern hemi-
sphere, near the Pole, where the extremities of Europe, Asia
and America unite or approach near to one another, a con-
siderable number of the same species of plants are found,
common to the three continents. But it has been remarked,,
that these plants, which are thus so widely diffused in the
Arctic regions, are also found in the chain of the Aleutian
islands, which stretch almost across from America to Asia, and
which may probably have served as the channel of communi-
cation for the partial blending of the Floras of the adjoining
regions. It has, indeed, been found to be a general rule, that
plants found at two points very remote from each other, occur
also in places intermediate.

In islands very distant from continents, the total number of
plants is comparatively small ; but a large proportion of the
species are such as occur nowhere else. In so far as the Flora
of such islands is not peculiar to them, it contains, in general,
species common to the nearest main lands *.

The islands of the great southern ocean exemplify these
rules ; the easternmost containing more American, and the
western more Indian plants f . Madeira and Teneriffe contain
many species, and even entire genera, peculiar to them ; but
they have also plants in common with Portugal, Spain, the
Azores, and the north-west coast of Africa |.

* Prichard, vol. i. p. 36. Brown, Appendix to Flinders,
f Forster, Observations, &e.

| Humboldt, Pers. Narr., vol. i. p.' 270 of the translation, Richard, Phys.
Hist, of Mankind, vol, i,"p. 37.

Ch. V.]

DISTINCT BOTANICAL REGIONS.

In the Canaries, out of five hundred and thirty-three species
of phanerogamous plants, it is said that three hundred and ten
are peculiar to these isles, and the rest identical with those of
the African continent ; but in the Flora of St. Helena, -which
is so far distant, even from the western shores of Africa, there
have been found, out of sixty-one native species, only two or
three which are to be found in any other part of the globe.

Decandolle has enumerated twenty great botanical provinces
inhabited by indigenous or aboriginal plants ; and although
many of these contain a variety of species which are common
to several others, and sometimes to places very remote, yet the
lines of demarcation are,, upon the whole, astonishingly well
defined*. Nor is it likely that the bearing of the evidence on
which these general views are founded will ever be materially
affected, since they are already confirmed by the examination
of seventy or eighty thousand species of plants.

The entire change of opinion which the contemplation of
these phenomena has brought about is worthy of remark. The
first travellers were persuaded that they should find, in distant
regions, the plants of their own country, and they took a plea-
sure in giving them the same names. It was some time before
this illusion was dissipated ; but so fully sensible did botanists
at last become of the extreme smallness of the number of
phsenogamous plants common to different continents, that the
ancient Floras fell into disrepute. All grew diffident of the
pretended identifications, and we now find that every naturalist
is inclined to examine each supposed exception with scrupulous
severity f. If they admit the fact, they begin to speculate on the
mode whereby the seeds may have been transported from one
country into the other, or inquire on which of two continents
the plant was indigenous, assuming that a species, like an
individual, cannot have two birth-places.

The marine vegetation is less known, but we learn from

* See a farther subdivision 'by which twenty-seven provinces are made, by M.
Alph. Decandolle, son of Decandolle. Monogr. des Campantdees. Paris, 1830.
f Decandolle, Essai Elemen, de Geog, Botan. p. 45.

MARINE VEGETATION.

[Ch. V.

Lamouroux, that it is divisible into different systems, apparently
as distinct as those on the land, notwithstanding that the uni-
formity of temperatui-e is so much greater in the ocean. For
on that ground we might have expected the phenomenon of
partial distribution to have been far less striking, since climate
is, in general, so influential a cause in checking the dispersion
of species from one zone to another.

The number of hydrophytes, as they are termed, is very
considerable, and their stations are found to be infinitely
more varied than could have been anticipated ; for while some
plants are covered and uncovered daily by the tide, others live
in abysses of the ocean, at the extraordinary depth of one thou-
sand feet ; and although in such situations there must reign
darkness more profound than night, at least to our organs,
many of these vegetables are highly coloured. From the
analogy of terrestrial plants we should have inferred that the
colouring of the algae was derived from the influence of the
solar rays ; yet we are compelled to doubt when we reflect
how feeble must be the rays which penetrate to these great
depths.

The subaqueous vegetation of the Mediterranean is, upon
the whole, distinct from that of the Atlantic on the west, and
that part of the Arabian gulf which is immediately con-
tiguous on the south. Other botanical provinces are found in
the West-Indian seas, including the gulf of Mexico; in the
ocean which washes the shores of South America, in the Indian
ocean and its gulfs, in the seas of Australia, and in the Atlantic
basin, from the 40° of north lat. to the pole. There are very
few species common to the coast of Europe and the United
States of North America, and none common to the Straits of
Magellan and the shores of Van Diemen's Land.

It must not be overlooked, that the distinctness alluded to
between the vegetation of these several countries relates strictly
to species and not to forms. In regard to the numerical pre-
ponderance of certain forms, and many peculiarities of internal
structure, there is_ a marked agreement in the vegetable pro-

Ch.V.]

DISPERSION OF SEEDS.

ductions of districts placed in corresponding latitudes, and
under similar physical circumstances,, however remote their
position. Thus there are innumerable points of analogy between
the vegetation of the Brazils, equinoctial Africa, and India ;
and there are also points of difference wherein the plants of
these regions are distinguishable from all extra-tropical groups.
But there are very few species common to the three continents.
The same may be said, if we compare the plants of the Straits
of Magellan with those of Van Diemeifs Land, or the vegeta-
tion of the United States with that of the middle of Europe:
the species are distinct, but the forms are in a great degree
analogous.

Let us now consider what means of diffusion, independently
of the agency of man, are possessed by plants, whereby, in the
course of ages, they may be enabled to stray from one of the
botanical provinces above mentioned to another, and to establish
new colonies at a great distance from their birth-place.

The principal of the inanimate agents, provided by nature
for scattering the seeds of plants over the globe, are the move-
ments of the atmosphere and of the ocean, and the constant
flow of water from the mountains to the sea. To beo-in
with the winds : a great number of seeds are furnished with
downy and feathery appendages, enabling them, when ripe, to
float in the air, and to be wafted easily to great distances by
the most gentle breeze. Other plants are fitted for dispersion
by means of an attached wing, as in the case of the fir-tree, so
that they are caught up by the wind as they fall from the cone,
and are carried to a distance. Amongst the comparatively
small number of plants known to Linnaeus, no less than one
hundred and thirty-eight genera are enumerated as having
winged seeds.

As winds often prevail for days, weeks, or even months
together, in the same direction, these means of transportation
may sometimes be without limits ; and even the heavier grains
may be borne through considerable spaces, in a very short
time, during ordinary tempests j for strong gales, which can

AGENCY OF THE WINDS IN THE

[Ch. V.

sweep along grains of sand, often move at the rate of about
forty miles an hour, and if the storm be very violent, at the
rate of fifty-six miles *. The hurricanes of tropical regions,
which root up trees and throw down buildings, sweep along at
the rate of ninety miles an hour, so that, for however short a
time they prevail, they may carry even the heavier fruits and
seeds over friths and seas of considerable width, and, doubt-
less, are often the means of introducing into islands the
vegetation of adjoining continents. Whirlwinds are also in-
strumental in bearing along heavy vegetable substances to
considerable distances. Slight ones may frequently be observed
in our fields, in summer, carrying up haycocks into the air,
and then letting fall small tufts of hay far and wide over the
country ; but they are sometimes so powerful as to dry up
lakes and ponds, and to break off the boughs of trees, and
carry them up in a whirling column of air.

Franklin tells us, in one of his letters, that he saw, in
Maryland, a whirlwind which began by taking up the dust
which lay in the road, in the form of a sugar-loaf with the
pointed end downwards, and soon after grew to the height
of forty or fifty feet, being twenty or thirty in diameter. It
advanced in a direction contrary to the wind, and although
the rotatory motion of the column was surprisingly rapid, its
Onward progress was sufficiently slow to allow a man to keep
pace with it on foot. Franklin followed it on horseback,
accompanied by his son, for three-quarters of a mile, and saw
it enter a wood, where it twisted and turned round large
trees with surprising force. These were carried up in a spiral
line, and were seen flying in the air, together with boughs
and innumerable leaves, which, from their height, appeared
reduced to the apparent size of flies. As this cause operates
at different intervals of time throughout a great portion of the
earth's surface, it may be the means of bearing not only plants
but insects, land-testacea and their eggs, with many other
species of animals, to points which they could never otherwise
* Annuaire du Bureau dea Longitudes.

Gh. V.] DISPERSION OF PLANTS. 75

have reached, and from which they may then begin to propa-
gate themselves again as from a new centre.

The seeds of some aquatic fresh- water plants are of the form
of shells, or small canoes, and on this account they swim on the
surface, and are carried along by the wind and stream. Others
are furnished with fibres, which serve the purpose of masts and
sails, so that they are impelled along by the winds, even where
there is no current. They cannot take root until the water
stagnates, or till they reach some sheltered corner, where they
may live without being exposed to too much agitation from
winds and currents *. The above-mentioned contrivances may
enable aquatic plants to diffuse themselves gradually to con-
siderable distances wherever there is a great chain of lakes, or
a river which traverses a large continent.

It has been found that a great numerical proportion of the
exceptions to the limitation of species to certain quarters of the
globe, occur in the various tribes of cryptogamic plants. Lin-
naeus observed, that as the germs of plants of this class, such
as mosses, fungi, and lichens, consist of an impalpable powder,
the particles of which are scarcely visible to the naked eye,
there is no difficulty to account for their being dispersed
throughout the atmosphere, and carried to every point of the
globe, where there is a station fitted for them. Lichens in
particular ascend to great elevations, sometimes growing two
thousand feet above the line of perpetual snow, at the utmost
limits of vegetation, and where the mean temperature is nearly
at the freezing point. This elevated position must contribute
greatly to facilitate the dispersion of those buoyant particles of
which their fructification consists f .

Some have inferred, from the springing up of mushrooms
whenever particular soils and decomposed organic matter are
mixed together, that the production of fungi is accidental, and
not analogous to that of perfect plants]:. But Fries, whose
authority on these questions is entitled to the highest respect,

* Rev. Dr. Rennie, Essays on the Nat. Hist, of Peat Moss, p. 248.
■j- Linn., Tour in Lapland, vol. ii. p. 282.
% Lindley, In.tr.od, to Nat, Syst, of Botany, who cites Fries,

76 DISPERSION OF PLANTS [Ch.V.

has shown the fallacy of this argument in favour of the old
doctrine of equivocal generation. « f The sporules of fungi,"
says this naturalist, " are so infinite, that in a single individual
of Reticularia maxima, I have counted above ten millions, and
so subtile as to be scarcely visible, often resembling thin smoke;
so light that they may be raised perhaps by evaporation into
the atmosphere, and dispersed in so many ways by the attrac-
tion of the sun, by insects, wind, elasticity, adhesion, &c, that
it is difficult to conceive a place from which they may be ex-
cluded."

In turning our attention, in the next place, to the instru-
mentality of the aqueous agents of dispersion, we cannot do
better than cite the words of one of our ablest botanical writers.
*' The mountain-stream or torrent," observes Keith, " washes
down to the valley the seeds which may accidentally fall into
it, or which it may happen to sweep from its banks when it
suddenly overflows them. The broad and majestic river,
winding along the extensive plain, and traversing the continents
of the world, conveys to the distance of many hundreds of miles
the seeds that may have vegetated at its source. Thus the
southern shores of the Baltic are visited by seeds which grew
in the interior of Germany 3 and the western shores of the
Atlantic by seeds that have been generated in the interior of
America Fruits, moreover, indigenous to America and
the West Indies, such as that of the Mimosa scandens, the
cashew-nut, and others, have been known to be drifted across
the Atlantic by the Gulf-stream, on the western coasts of
Europe, in such a state that they might have vegetated had
the climate and soil been favourable. Among these the Gui-
landina Bonduc, a leguminous plant, is particularly mentioned,
as having been raised from a seed found on the west coast of
Ireland f- Sir Hans Sloane informs us that the lenticula
marina, or sargasso, a bean which is frequently cast ashore on
the Orkney isles, and coast of Ireland, grows on the rocks
about Jamaica, where the surface of the sea is sometimes

* System of Physiological Botany, vol. ii. p. 405.
t Brown, Append, to Tucfcey, No. V. p. 481.

€h. V.]

BY WINDS AND CURRENTS.

strewed with it, and from whence it is known to be carried by
the winds and currents towards the coast of Florida *.

The absence of liquid matter in the composition of seeds
renders them comparatively insensible to heat and cold, so
that they may be carried, without detriment, through climates
where the plants themselves would instantly perish. Such
is their power of resisting the effects of heat, that Spallanzani
mentions some seeds that germinated after having been boiled
in water f. When, therefore, a strong gale, after blowing
violently off the land for a time, dies away, and the seeds
alight upon the surface of the waters, or wherever the ocean,
by eating away the sea-cliffs, throws down into its waves plants
which would never otherwise approach the shores, the tides
and currents become active instruments in assisting the dis-
semination of almost all classes of the vegetable kingdom.

In a collection of six hundred plants from the neighbour-
hood of the river Zaire, in Africa, Mr. Brown found that
thirteen species were also met with on the opposite shores of
Guiana and Brazil. He remarked, that most of these plants
were only found on the lower parts of the river Zaire, and
were chiefly such as produced seeds capable of retaining their
vitality a long time in the currents of the ocean.

Islands, moreover, and even the smallest rocks, play an im-
portant part in aiding such migrations, for when seeds alight
upon them from the atmosphere, or are thrown up by the surf,
they often vegetate and supply the winds and waves with a
repetition of new and uninjured crops of fruits and seeds, which
may afterwards pursue their course through the atmosphere,
or along the surface of the sea, in the same direction. The
number of plants found at any given time on an islet affords
no test whatever of the extent to which it may have co-operated
towards this end, since a variety of species may first thrive
there and then perish, and be followed by other chance-comers
like themselves.

Currents and winds, in the arctic regions, drift along ice-

* Phil. Trans. 1695. f System of Philosophical Botany, vol. ii. p. 403,

AGENCY OF ANIMALS

[Ch. V.

bergs covered with an alluvial soil on which herbs and pine
saplings are seen growing, which often continue to vegetate
on some distant shore where the ice-island is stranded.

With respect to marine vegetation, the seeds being in their
native element, may remain immersed in water without injury
for indefinite periods, so that there is no difficulty in conceiving
the diffusion of species wherever uncongenial climates, contrary
currents, and other causes, do not interfere. All are familiar
with the sight of the floating sea-weed

" Flung from the rock on ocean's foam to sail.
Where'er the surge may sweep, the tempest's breath prevail."

Remarkable accumulations of drift weed occur on each side
of the equator in the Atlantic, Pacific^ and Indian Oceans.
Columbus and other navigators who first encountered these
banks of algse in the Northern Atlantic, compared them to
vast inundated meadows, and state that they retarded the
progress of their vessels. The most extensive bank is a little
west of the meridian of Fayal, one of the Azores, between
latitude 25° and 36°; violent north winds sometimes prevail
in this space, and drive the sea- weed to low latitudes, as far as
the 24th or even the 20th degree*.

The hollow pod-like receptacles in which the seeds of many
algae are lodged, and the filaments attached to the seed-vessels
of others, seem intended to give buoyancy, and we may observe
that these hydrophytes are in general proliferous, so that the
smallest fragment of a branch can be developed into a perfect
plant. The seeds, moreover, of the greater number of species
are enveloped with a mucous matter like that which surrounds
the eggs of some fish, and which not only protects them from
injury, but serves to attach them to floating bodies or to rocks.

But we have as yet considered part only of the fertile re-
sources of nature for conveying seeds to a distance from their
place of growth. The various tribes of animals are busily
engaged in furthering an object whence they derive such im-
portant advantages. Sometimes an express provision is found

* Greville, Introduction to Algse Britannicse, p, 12,

Gh. V.]

IN DIFFUSING PLANTS.

in the structure of seeds to enable them to adhere firmly by
prickles, hooks, and hairs, to the coats of animals, or feathers
of the winged tribe, to which they remain attached for weeks,
or even months, and are borne along into every region whither
birds or quadrupeds may migrate. Linnaeus enumerates fifty
genera of plants, and the number now known to botanists is
much greater, which are armed with hooks by which, when
ripe, they adhere to the coats of animals. Most of these
vegetables, he remarks, require a soil enriched with dung.
Few have failed to mark the locks of wool hanging on the
thorn-bushes, wherever the sheep pass, and it is probable that
the wolf or lion never give chace to herbivorous animals with-
out being unconsciously subservient to this part of the vege-
table economy.

A deer has strayed from the herd, when browsing on some
rich pasture, when he is suddenly alarmed by the approach
of his foe. He instantly plunges through many a thicket,
and swims through many a river and lake. The seeds of the
herbs and shrubs adhere to his smoking flanks, and are washed
off again by the streams. The thorny spray is torn off and
fixes itself in his hairy coat, until brushed off again in other
thickets and copses. Even on the spot where the victim is
devoured, many of the seeds which he had swallowed imme-
diately before the pursuit may be left on the ground uninjured.

The passage, indeed, of undigested seeds through the sto-
machs of animals is one of the most efficient causes of the dis-
semination of plants, and is of all others, perhaps, the most
likely to be overlooked. Few are ignorant that a portion of
the oats eaten by a horse preserve their germinating faculty in
the dung. The fact of their being still nutritious is not lost
on the sagacious rook. To many, says Linnaeus, it seems
extraordinary, and something of a prodigy, that when a field
is well tilled and sown with the best wheat, it frequently pro-
duces darnel or the wild oat, especially if it be manured with
new dung : they do not consider that the fertility of the smaller
seeds is not destroyed in the ventricles of animals *.

f Linnseus, Amcen, Acad., vol, ii, p. 409,

AGENCY OP BIRDS

[Ch. V.

Some of the order of the Passeres, says Ekmarck *, devour
the seeds of plants in great quantities, which they eject again
in very distant places, without destroying its faculty of vege-
tation ; thus a flight of larks will fill the cleanest field with a
great quantity of various kinds of plants, as the melilot trefoil
(Medicago lupulina), and others whose seeds are so heavy that
the wind is not able to scatter them to any distance. In like
manner, the blackbird and missel-thrush, when they devour
berries in too great quantities, are known to consign them to
the earth undigested in their excrement f .

Pulpy fruits serve quadrupeds and birds as food, while their
seeds, often hard and indigestible, pass uninjured through the
intestines, and are deposited far from their original place of
growth in a condition peculiarly fit for vegetation J. So well
are our farmers, in some parts of England, aware of this fact,
that when they desire to raise a quick-set hedge in the shortest
possible time, they feed turkeys with the haws of the com-
mon white- thorn (Crataegus oxy acantha) , and then sow the
stones which are ejected in their excrement, whereby they
gain an entire year in the growth of the plant §. Birds
when they pluck cherries, sloes, and haws, fly away with
them to some convenient place, and when they have devoured
the fruit drop the stone into the ground. Captain Cook, in
his account of the volcanic island of Tanna, one of the New
Hebrides, which he visited in his second voyage, makes the
following interesting observation. " Mr. Forster, in his bota-
nical excursion this day, shot a pigeon, in the craw of which
was a wild nutmeg. He took some pains to find the tree on
this island, but his endeavours were without success ||." It is
easy, therefore, to perceive, that birds in their migrations to
great distances, and even across seas, may transport seeds to
new isles and continents.

* Amoen. Acad., vol. iv., Essay 75, § 8.
t Wilcke, Amoen. Acad., vol. vi. § 22.
% Smith's Introd. to Phys. and Syst. Botany, p. 304, 1807.
§ This information was communicated to me by Professor Henslow, of
Cambridge. || Book iii v ch. 4,

Ch. V.]

IN DIFFUSING PLANTS.

The sudden deaths to which great numbers of frugivorous
birds are annually exposed, must not be omitted as auxiliary
to the transportation of seeds to new habitations. When the
sea retires from the shore, and leaves fruits and seeds on the
beach, or in the mud of estuaries, it might, by the return-
ing tide, wash them away again, or destroy them by long
immersion ; but when they are gathered by land birds which
frequent the sea-side, or by waders and water-fowl, they are
often borne inland, and if the bird to whose crop they have been
consigned is killed, they may be left to grow up far from the
sea. Let such an accident happen but once in a century, or a
thousand years, it will be sufficient to spread many of the
plants from one continent to another ; for, in estimating the
activity of these causes, we must not consider whether they act
slowly in relation to the period of our observation, but in refer-
ence to the duration of species in general.

Let us trace the operation of this cause in connexion with
others. A tempestuous wind bears the seeds of a plant many
miles through the air, and then delivers them to the ocean ;
the oceanic current drifts them to a distant continent; by the
fall of the tide they become the food of numerous birds, and
one of these is seized by a hawk or eagle, which, soaring across
hill and dale to a place of retreat, leaves, after devouring its
prey, the unpalatable seeds to spring up and flourish in a new
soil.

The machinery before adverted to is so capable of dissem-
inating seeds over almost unbounded spaces, that were we
more intimately acquainted with the economy of nature, we
might probably explain all the instances which occur of the
aberration of plants to great distances from their native coun-
tries. The real difficulty which must present itself to every
one who contemplates the present geographical distribution of
species, is the small number of exceptions to the rule of the non-
intermixture of different groups of plants. Why have they not,
supposing them to have been ever so distinct originally, become
more blended and confounded together in the lapse of ages ?
Vol. II. Gr

AGENCY OF MAN IN THE

[Ch. V.

But in addition to all the agents already enumerated as
instrumental in diffusing plants over the globe, we have still to
consider man — one of the most important of all. He transports
with him, into every region, the vegetables which he cultivates
for his wants, and is the involuntary means of spreading a still
greater number which are useless to him, or even noxious.
** When the introduction of cultivated plants is of recent date,
there is no difficulty in tracing their origin ; but when it is of
high antiquity, we are often ignorant of the true country of the
plants on which we feed. No one contests the American origin
of the maize or the potato, nor the origin, in the old world, of
the coffee-tree and of wheat. But there are certain objects
of culture, of very ancient date, between the tropics, such, for
example, as the banana, of which the origin cannot be verified.
Armies, in modern times, have been known to carry,, in all
directions, grain and cultivated vegetables from one extremity
of Europe to the other, and thus have shown us how, in more
ancient times, the conquests of Alexander, the distant expedi-
tions of the Romans, and afterwards the Crusades, may have
transported many plants from one part of the world to the
other *."

But besides the plants used in agriculture, the number which
have been naturalized by accident, or which man has spread
unintentionally, is considerable. One of our old authors, Jos-
selyn, gives a catalogue of such plants as had, in his time,
sprung up in the colony since the English planted and kept
cattle in New England. They were two and twenty in number.
The common nettle was the first which the settlers noticed,
and the plantain was called by the Indians, " English man's
foot," as if it sprung from their footsteps f .

" We have introduced everywhere," observes Decandolle,
tc some weeds which grow among our various kinds of wheat,
and which have been received, perhaps, originally from Asia
with them . Thus, together with the Barbary wheat, the inhabi-

* Decandolle, Essai E16men. &c. p. 50.
f Quarterly Review, vol, xxx., p. 8.

Ch. V.]

DISPERSION OF PLANTS.

tants of the south of Europe have sown, for many ages,the plants
of Algiers and Tunis. With the wools and cottons of the
East, or of Barbary, there are often brought into France, the
grains of exotic plants, some of which naturalize themselves.
Of this I will cite a striking example. There is at the gate of
Montpelier, a meadow set apart for drying foreign wool after
it has been washed. There hardly passes a year without some
foreign plants being found naturalized in this drying ground.
I have gathered there Centaurea parviflora, Psoralea palsestina,
and Hypericum crispum." This fact is not only illustrative
of the aid which man lends inadvertently to the propagation of
plants, but it also demonstrates the multiplicity of seeds which
are borne about in the woolly and hairy coats of wild animals.

The same botanist mentions instances of plants naturalized
in sea-ports by the ballast of ships, and several examples of
others which have spread through Europe from botanical gar-
dens, so as to have become more common than many indigenous
species.

It is scarcely a century, says Linnaeus *, since the Canadian
erigiron, or flea-bane, was brought from America to the bota-
nical garden at Paris,, and already the seeds have been carried
by the winds, so that it is diffused over France, the British
islands, Italy, Sicily, Holland, and Germany. Several others
are mentioned by the Swedish naturalist, as having been dis-
persed by similar means. The common thorn-apple, Datura
stramonium, observes Willdenow, now grows as a noxious weed
throughout all Europe, with the exception of Sweden, Lapland,
and Russia. It came from the East Indies and Abyssinia to
us, and was so universally spread by certain quacks who used
its seed as an emetic f .

In hot and ill-cultivated countries, such naturalizations take
place more easily. Thus the Chenopodium ambrosioides,
sown by Mr. Burchell on a point of St. Helena, multiplied so

* Essay on the Habitable Earth, Amoen. Acad. vol. ii. p. 409.
f Principles of Botany, p. 389.

G 2

84 AGENCV OF MAN IN THE [Ch. V.

in four years as to become one of the commonest weeds in the
island *.

The most remarkable proof, says Decandolle, of the extent
to which man is unconsciously the instrument of dispersing
and naturalizing species, is found in the fact, that in New Hol-
land, America, and the Cape of Good Hope, the aboriginal
European species exceed in number all the others which have
come from any distant regions, so that, in this instance, the
influence of man has surpassed that of all the other causes
which tend to disseminate plants to remote districts.

Although we are but slightly acquainted, as yet, with the
extent of our instrumentality in naturalizing species, yet the
facts ascertained afford no small reason to suspect that the
number which we introduce unintentionally, exceeds all those
transported by design. Nor is it unnatural to suppose that the
functions, which the inferior beings extirpated by man once dis-
charged in the economy of nature, should devolve upon the
human race. If we drive many birds of passage from different
countries, we are probably required to fulfil their office of car-
rying seeds, eggs of fish, insects, molluscs, and other creatures,
to distant regions ; if we destroy quadrupeds, we must replace
them, not merely as consumers of the animal and vegetable
substances which they devoured, but as disseminators of plants,
and of the inferior classes of the animal kingdom. We do not
mean to insinuate that the same changes which man brings
about, would have taken place by means of the agency of other
species, but merely that he supersedes a certain number of
agents, and so far as he disperses plants unintentionally, or
against his will, his intervention is strictly analogous to that of
the species so extirpated.

We may observe, moreover, that if, at former periods, the
animals inhabiting any given district have been partially altered
by the extinction of some species, and the introduction of
others, whether by new creations or by immigration, a change
must have taken place in regard to the particular plants con-

* Principles of Botany, p. 389.

Ch. V.]

DISPERSION OF PLANTS.

veyed about with them to foreign countries. As for example,
when one set of migratory birds is substituted for another, the
countries from and to which seeds are transported are imme-
diately changed. Vicissitudes, therefore, analogous to those
which man has occasioned, may have previously attended the
springing up of new relations between species in the vegetable
and animal worlds.

It may also be remarked, that if man is the most active agent
in enlarging, so also is he in circumscribing the geographical
boundaries of particular plants. He promotes the migration
of some, he retards that of other species, so that while in many
respects he" appears to be exerting his power to blend and
confound the various provinces of indigenous species, he is,
in other ways, instrumental in obstructing the fusion into one
group of the inhabitants of contiguous provinces.

Thus, for example, when two botanical regions exist in the
same great continent, such as the European reyion, compre-
hending the central parts of Europe and those surrounding
the Mediterranean, and the Oriental region, as it has been
termed, embracing the countries adjoining the Black Sea and
the Caspian, the interposition between these of thousands of
squares miles of cultivated lands, opposes a new and powerful
barrier against the mutual interchange of indigenous plants.
Botanists are well aware that garden plants naturalize and dif-
fuse themselves with great facility in comparatively unreclaimed
countries, but spread themselves slowly and with difficulty in
districts highly cultivated. There are many obvious causes
for this difference ; by drainage and culture the natural variety
of stations is diminished, and those stray individuals by which
the passage of a species from one fit station to another is
effected, are no sooner detected by the agriculturist, than they
are uprooted as weeds. The larger shrubs and trees, in par-
ticular, can scarcely ever escape observation, when they have
attained a certain size, and will rarely fail to be cut down if
unprofitable.

The same observations are applicable to the interchange of

DIFFUSION GF PLANTS.

[Ch. V;

the insects, birds, and quadrupeds of two regions situated like
those above alluded to. No beasts of prey are permitted to
make their way across the intervening arable tracts^ Many
birds, and hundreds of insects, which would have foUnd some
palatable food amongst the various herbs and trees of the pri-
meval wilderness, are unable to subsist on the olive, the vine,
the wheat, and a few trees and grasses favoured by man. In
addition, therefore, to his direct intervention, man, in this case,
operates indirectly to impede the dissemination of plants, by
intercepting the migrations of animals, many of which would
otherwise have been active in transporting seeds from one pro-
vince to another.

Whether in the vegetable kingdom the influence of man will
tend, after a considerable lapse of ages, to render the geogra-
phical range of species in general more extended, as DeCandolle
seems to anticipate, or whether the compensating agency above
alluded to will not counterbalance the exceptions caused by our
naturalizations, admits at least of some doubt. In the attempt
to form an estimate on this subject, we must be careful not to
underrate, or almost overlook, as some appear to have done,
the influence of man in checking the diffusion of plants, and
restricting their distribution to narrower limits.

CHAPTER VI.

Geographical Distribution of Animals— Buffon on the specific distinctness of
the quadrupeds of the old and new world — Different regions of indigenous
mammalia — Quadrupeds in islands — Range of the Cetacea — Dissemination of
quadrupeds — their powers of swimming — Migratory instincts — Drifting of
quadrupeds on ice-floes — On floating islands of drift timber — Migrations of
Cetacea — Habitations of Birds — Their migrations and facilities of diffusion-r-
Distribution of Reptiles and their powers of dissemination.

Although in speculating on " philosophical possibilities,"
said Buffon, the same temperature might have been expected,
all other circumstances being equal, to produce the same beings
in different parts of the globe, both in the animal and vegetable
kingdoms, yet it is an undoubted fact, that when America was
discovered, its indigenous quadrupeds were all dissimilar from
those previously known in the old world. The elephant, the
rhinoceros, tile hippopotamus, the cameleopard, the camel,
the dromedary, the buffalo, the horse, the ass, the lion, the
tiger, the apes, the baboons, and a number of other mammalia,
where nowhere to be met with on the new continent ; while
in the old, the American species, of the same great class, were
nowhere to be seen — the tapir, the lama, the pecari, the jaguar,
the couguar, the agouti, the paca, the coati, and the sloth.

These phenomena, although few in number relatively to the
whole animate creation, were so striking and so positive in their
nature, that the French naturalist caught sight at once of a
general law in the geographical distribution of organic beings,
namely, the limitation of groups of distinct species to regions
separated from the rest of the globe by certain natural barriers.
It was, therefore, in a truly philosophical spirit that, relying
on the clearness of the evidence obtained respecting the larger
quadrupeds, he ventured to call in question the identifications
announced by some contemporary naturalists, of species of

DISTRIBUTION OF

[Ch. VI.

animals said to be common to the southern extremities of
America and Africa *.

The migration of quadrupeds from one part of the globe to
the other, observes one of our ablest writers, is prevented by
uncongenial climates and the branches of the ocean which
intersect continents. es Hence by a reference to the geogra-
phical site of countries, we may divide the earth into a certain
number of regions fitted to become the abodes of particular
groups of animals, and we shall find, on inquiry, that each
of these provinces, thus conjecturally marked out, is actually
inhabited by a distinct nation of quadrupeds f -P

Where the continents of the old and new world approxi-
mate to each other towards the north, the narrow straits
which separate them are frozen over in winter, and the dis-
tance is further lessened by intervening islands. Thus a
passage from one continent to another becomes practicable to
such quadrupeds as are fitted to endure the intense cold of the
arctic circle. Accordingly, the whole arctic region has become
one of the provinces of the animal kingdom, and contains many
species common to both the great continents. But the tem-
perate regions of America, which are separated by a wide
extent of ocean from those of Europe and Asia, contain each
a distinct nation of indigenous quadrupeds. There are three
groups of tropical mammalia belonging severally to America,
Africa, and continental India, each inhabiting lands separated
from each other by the ocean.

In Peru and Chili, says Humboldt, the region of the grasses,
which is at an elevation of from twelve thousand three hun-
dred to fifteen thousand four hundred feet, is inhabited by
crowds of lama, guanaco, and alpaca. These quadrupeds,
which here represent the genus camel of the ancient continent,

* Buffon, vol. v.— On the Virginian Opossum,
f Prichard's Phys. Hist, of Mankind, vol. i. p. 54. In some of the preliminary
chapters will be found a sketch of the leading facts illustrative of the geogra-
phical distribution of animals, drawn up with the author's usual clearness and
ability.

Ch. VI.]

MAMMIFEROUS QUADRUPEDS.

have not extended themselves either to Brazil or Mexico,
because, during their journey, they must necessarily have
descended into regions that were too hot for them *,

New Holland is well known to contain a most singular and
characteristic assemblage of mammiferous animals, consisting
of more than forty species of the marsupial family, of which no
congeners even occur elsewhere, with the exception of a few
American opossums. This exclusive occupation of the Aus-
tralian continent by the kangaroos and other tribes of pouched
animals, although it has justly excited great attention, is a fact,
nevertheless^ in strict accordance with the general laws of the
distribution of species ; since, in other parts of the globe, we
find peculiarities of form, structure, and habit, in birds, rep-
tiles, insects, or plants, confined entirely to one hemisphere, or
one continent, and sometimes to much narrower limits.

The southern region of Africa, where that continent extends
into the temperate zone, constitutes another separate zoological
province, surrounded as it is on three sides by the ocean, and
cut off from the countries of milder climate, in the northern
hemisphere, by the intervening torrid zone. In many instances,
this region contains the same genera which are found in tem-
perate climates to the northward of the line ; but then the
southern are different from the northern species. Thus in
the south we find the quagga and the zebra : in the north, the
horse, the ass, and the jiggetai of Asia.

The south of Africa is spread out into fine level plains from
the tropic to the Cape ; in this region, says Pennant, besides the
horse genus, of which five species have been found, there are
also peculiar species of rhinoceros, the hog, and the hyrax,
among pachydermatous races ; and amongst the ruminating,
the giraffe, the Cape buffalo, and a variety of remarkable ante-
lopes, as the springbok, the oryx, the gnou, the leucophoe, the
pygarga, and several others f.

* Description of the Equatorial Regions,
f Pennant's Hist, of Quadrupeds, cited by Prichard, Phys. Hist, of Mankind,
vol. i, p. 66.

DISTRIBUTION OP

CCh, VI.

The Indian archipelago presents peculiar phenomena in
regard to its indigenous mammalia, which, in their generic
character, recede in some respects from that of the animals of
the Indian continent, and approximate to the African. The
Sunda isles contain a hippopotamus, which is wanting in the
rivers of Asia ; Sumatra, a peculiar species of tapir, and a
rhinoceros resembling the African more than the Indian species,
but specifically distinguishable from both # .

Beyond the Indian archipelago is an extensive region, in-
cluding New Guinea, New Britain, and New Ireland, together
with the archipelago of Solomon's islands^ the New Hebrides,
and Louisiade, and the more remote groups of isles in the great
southern ocean, which may be considered as forming one zoo-
logical province. Although these remarkable countries are
extremely fertile in their vegetable productions, they are almost
wholly destitute of native warm-blooded quadrupeds, except a
few species of bats, and some domesticated animals in the pos-
session of the natives f.

Quadrupeds found on islands situated near the continents,
generally form a part of the stock of animals belonging to the
adjacent main land ; " but small islands remote from continents
are in general altogether destitute of land quadrupeds, except
such as appear to have been conveyed to them by men. Ker-
guelen's Land, Juan Fernandez, the Gallapagos, and the Isles
de Lobos, are examples of this fact. Among all the groups of
fertile islands in the Pacific ocean, no quadrupeds have been
found, except dogs, hogs, rats, and a few bats. The bats have
been found in New Zealand and the more westerly groups ;
they may probably have made their way along the Chain of
islands which extend from the shores of New ; Guinea far into
the southern Pacific. The hogs and the dogs appear to have
been conveyed by the natives from New Guinea. The Indian
isles, near New Guinea, abound in oxen, buffaloes, goats, deer,
hogs, dogs, cats, and rats ; but none of them are said to have

* Prichard, Phys. Hist, of Mankind, p. 66 ; Cuvier, Ann. du Museum, torn. vii.

f Prichard, ibid., p. 56.

Ch. VI.]

MAMMIFEROUS QUADRUPEDS.

reached New Guinea, except the hog and the dog. The New
Guinea hog is of the Chinese variety* and was probably brought
from some of the neighbouring isles, being the animal most in
request among savages. It has run wild in New Guinea.
Thence it has been conveyed to the New Hebrides, the Tonga
and Society isles, and to the Marquesas ; but it is still wanting
in the more easterly islands, and, to the southward, in New
Caledonia*

" Dogs may be traced from New Guinea to the New Hebrides
and Fiji isles ; but they are wanting in the Tonga isles,
though found among the Society and Sandwich islanders,
by some of whom they are used for food : to the southward
they have been conveyed to New Caledonia and New Zealand.
In Easter Island, the most remotely situated in this ocean, there
are no domestic animals except fowls and rats, which are eaten
by the natives : these animals are found in most of the islands *,
the fowls are probably from New Guinea. Rats are to be
found even on some desert islands, whither they may have
been conveyed by canoes which have occasionally approached
the shores. It is known, also, that rats occasionally swim in
large numbers to considerable distances

It is natural to suppose that the geographical range of the
different species of cetacea should be less correctly ascertained
than that of the terrestrial mammifers. It is, however, well
known, that the whales which are obtained by our fishers in the
South Seas, are distinct from those of the North ; and the
same dissimilarity has been found in all the other marine ani-
mals of the same class^ so far as they have yet been studied by
naturalists.

Let us now inquire what facilities the various land quadru-
peds enjoy of spreading themselves over the surface of the earth.
In the first place, as their numbers multiply, all of them,
whether they feed on plants, or prey on other animals, are
disposed to scatter themselves gradually over as wide an area
as is accessible to them. But before they have extended their

? Prichard, Phys. Hist, of Mankind, vol. i. ; p, 75.

98 DISPERSION OF [Q\ h yi.

migrations over a large space, they are usually arrested either
by the sea, or a zone of uncongenial climate, or some lofty and
unbroken chain of mountains, or a tract already occupied by a
hostile and more powerful species.

Rivers and narrow friths can seldom interfere with their
progress, for the greater part of them swim well, and few are
without this power when urged by danger and pressing want.
Thus, amongst beasts of prey, the tiger is seen swimming about
among the islands and creeks in the delta of the Ganges, and
the jaguar traverses with ease the largest streams in South
America *. The bear, also, and the bison, stem the current of
the Mississippi. The popular error, that the common swine
cannot escape by swimming when thrown into the water, has
been contradicted by several curious and well-authenticated
instances during the recent floods in Scotland, One pig, only
six months old, after having been carried down from Garmouth
to the bar at the mouth of the Spey, a distance of a quarter of
a mile, swam four miles eastward to Port Gordon and landed
safe. Three others, of the same age and litter, swam at the
same time five miles to the west, and landed at Blackhill +.

In an adult and wild state, these animals would doubtless
have been more strong and active, and might, when hard
pressed, have performed a much longer voyage. Hence islands
remote from the continent may obtain inhabitants by casualties
which, like the late storms in Morayshire, may only occur once
in many centuries, or thousands of years, under all the same
circumstances. It is obvious that powerful tides, winds, and
currents, may sometimes carry along quadrupeds capable, in
like manner, of preserving themselves for hours in the sea to
very considerable distances, and in this way, perhaps, the tapir
{Tapir Indicus) may have become common to Sumatra and
the Malayan peninsula.

To the elephant in particular, the power of crossing rivers is
essential in a wild state, for the quantity of food which a herd

* Buffon, vol. v. p. 204.
f Sir T. D. Lauder, Bart, on the Floods in Morayshire, August, 1829., p. 302,
second edition.

Ch. VI.] MAMMIFEROUS QUADRUPEDS. 93

of these animals consumes renders it necessary that they should
be constantly moving from place to place. The elephant
crosses the stream in two ways. If the bed of the river be hard,
and the water not of too great a depth, he fords it. But when
he crosses great rivers, such as the Ganges and the Niger, the
elephant swims deep, so deep that the end of his trunk only is
out of the water * ; for it is a matter of indifference to him
whether his body be completely immersed, provided he can
bring the tip of his trunk to the surface, so as to breathe the
external air.

Animals of the deer kind frequently take to the water,
especially in the rutting season, when the stags are seen swim-
ming for several leagues at a time, from island to island, in
search of the does, especially in the Canadian lakes ; and in
some countries where there are islands near the sea-shore, they
fearlessly enter the sea and swim to them. In hunting excur-
sions, in North America, the elk of that country is frequently
pursued for great distances through the water.

The large herbivorous animals, which are gregarious, can
never remain long in a confined region, as they consume so
much vegetable food. The immense herds of bisons which
often, in the great valley of the Mississippi, blacken the surface
near the banks of that river and its tributaries, are continually
shifting their quarters, followed by wolves which prowl about
in their rear. ec It is no exaggeration," says Mr. James, " to
assert, that in one place, on the banks of the Platte, at least ten
thousand bisons burst on our sight in an instant. In the
morning we again sought the living picture, but upon all the
plain, which last evening was so teeming with noble animals,
not one remained f

Besides the disposition common to the individuals of every
species slowly to extend their range in search of food, in propor-
tion as their numbers augment, a migratory instinct often
develops itself in an extraordinary manner, when, after an

* Lib. Entert. Know., Quadrupeds, vol. ii. p. 63.
f Expedition from Pittsburgh to the Rocky Mountains, vol. ii. p. 153.

MIGRATIONS OF

[Ch. VI.

unusually prolific season, or upon a sudden scarcity of pro-
visions, great multitudes are threatened by famine. We shall
enumerate several illustrations of these migrations, because
they may put us upon our guard against attributing a high
antiquity to a particular species merely because it is diffused
over a great space ; they show clearly how soon, in a state of
nature, a newly-created species might spread itself, in every
direction, from a single point.

In very severe winters, great numbers of the black bears of
America migrate from Canada into the United States ; but
in milder seasons, when they have been well fed, they remain
and hybernate in the north §, The rein-deer, which in Scan-
dinavia can scarcely exist to the south of the sixty-fifth parallel,
descends, in consequence of the greater coldness of the climate,,
to the fiftieth degree, in Chinese Tartary, and often roves
into a country of more southern latitude than any part of
England.

In Lapland, and other high latitudes, the common squirrels,
whenever they are compelled,~by want of provisions, to quit
their usual abodes, migrate in amazing numbers, and travel
directly forwards, allowing neither rocks, forests, nor the
broadest waters, to turn them from their course. Great num-
bers are often drowned in attempting to pass friths and rivers.
In like manner the small Norway rat sometimes pursues its
migrations in a straight line across rivers and lakes ; and Pen-
nant informs us, that when, in Kamtschatka, the rats become
too numerous, they gather together in the spring, and proceed
in great bodies westward, swimming over rivers, lakes, and
arms of the sea. Many are drowned or destroyed by water-
fowl or fish. As soon as they have crossed the river Penchim,
at the head of the gulf of the same name, they turn southward,
and reach the rivers Judoma and Ochot by the middle of J nly,
a district surprisingly distant from their point of departure.

The lemings, also, of Scandinavia, often pour down in
myriads from the northern mountains and devastate the coun-

* Kichardson's Fauna Boreali-Americana, p. 16.

Ch. VI.]

MAMMIFEROUS QUADRUPEDS.

try. They generally move in lines which are about three feet
from each other, and exactly parallel, and they direct their
march from the north-west to the south-east, going directly
forward through rivers and lakes, and when they meet with
stacks of hay or corn, gnawing their way through them instead
of passing round *.

Vast troops of the wild ass, or onager of the ancients, which
inhabit the mountainous deserts of Great Tartary, feed, during
the summer, in the tracts east and north of Lake Aral. In the
autumn they collect in herds of hundreds, and even thousands,
and direct their course towards the north of India, and often to
Persia, to enjoy a warm retreat during winter f. Bands of two
or three hundred quaggas, a species of wild ass, are some-
times seen to migrate from the tropical plains of southern Africa
to the vicinity of the Malaleveen river. During their migra-
tions they are followed by lions, who slaughter them night by
night J.

The migratory swarms of the springbok, or Cape antelope,
afford another illustration of the rapidity with which a species,
under certain circumstances, may be diffused over a continent.
When the stagnant pools of the immense deserts south of the
Orange river dry up, which often happens after intervals of
three or four years, myriads of these animals desert the parched
soil, and pour down like a deluge on the cultivated regions
nearer the Cape. The havoc committed by them resembles
that of the African locusts ; and so crowded are the herds, that
" the lion has been seen to walk in the midst of the compressed
phalanx with only as much room between him and his victims
as the fears of those immediately around could procure by
pressing outwards

Dr. Horsfield mentions a singular fact in regard to the geo~

* Phil. Trans., vol. ii. p. 872. f Wood's Zoography, yol. i. p. 11.

I On the authority of Mr. Campbell. Library of Entert. Know., Menageries,
vol. i. p. 152.

§ Cuvier's Animal Kingdom, by Griffiths, vol. ii. p. 109. Library of Entert.
Know.; Menageries, vol. i. p, 366,

DRIFTING OF QUADRUPEDS ON

[Ch. VI.

graphical distribution of the Mydaus meliceps, a kind of pole-
cat inhabiting Java. This animal is u confined exclusively to
those mountains which have an elevation of more than seven
thousand feet above the level of the ocean : on these it occurs
with the same regularity as many plants. The long-extended
surface of Java, abounding with conical points which exceed
this elevation, affords many places favourable for its resort.
On ascending these mountains, the traveller scarcely fails to
meet with this animal, which, from its peculiarities, is univer-
sally known to the inhabitants of these elevated tracts, while to
those of the plains it is as strange as an animal from a foreign
country. In my visits to the mountainous districts, I uni-
formly met with it, and, as far as the information of the natives
can be relied on, it is found on all the mountains *."

NoWj if we were asked to conjecture how the Mydaus arrived
at the elevated regions of each of these isolated mountains, we
should say that before the isle was peopled by man, by whom
their numbers are now thinned, they may occasionally have
multiplied so as to be forced to collect together and migrate ; in
which case, notwithstanding the slowness of their motions,
some few would succeed in reaching another mountain, some
twenty, or even, perhaps, fifty miles distant: for although
the climate of the hot intervening plains would be unfavour-
able to them, they might support it for a time, and would find
there abundance of insects on which they feed. Volcanic erup-
tions, which at different times have covered the summits of
some of these lofty cones with steril sand and ashes, may have
occasionally contributed to force on these migrations.

The power of the terrestrial mammalia r to cross the sea is
very limited, and we have already stated that the same species
is scarcely ever common to districts widely separated by the
ocean. If there be some exceptions to this rule they generally
admit of explanation, for there are natural means whereby some
animals may be floated across the water, and the sea sometimes
wears a passage through a neck of land, leaving individuals

* Zoological Researches in Java, No. 2.

Ch. VI.]

ICE-FLOES AND FLOATING ISLANDS.

of a species on each side of the new channel. Polar bears are
known to have been frequently drifted on the ice from Green-
land to Iceland ; they can also swim to considerable distances,
for Captain Parry, on the return of his ships through Barrow's
Strait, met with a bear swimming in the water about midway
between the shores, which were about forty miles apart, and
where no ice was in sight*. " Near the east coast of Green-
land/' observes Scoresby, u they have been seen on the ice in
such quantities, that they were compared to flocks of sheep on
a common — and they are often found on field-ice, above two
hundred miles from the shore f." Wolves, in the arctic regions,
often venture upon the ice near the shore, for the purpose of
preying upon young seals which they surprise when asleep.
When these ice-floes get detached, the wolves are often carried
out to sea, and though some may be drifted to islands or conti-
nents, the greater part of them perish, and have been often heard
in this situation howling dreadfully, as they die by famine |.

During the short summer which visits Melville Islands
various plants push forth their leaves and flowers the moment
the snow is off the ground, and form a carpet spangled with
the most lively colours. These secluded spots are reached
annually by herds of musk-oxen and rein-deer, which travel
immense distances over dreary and desolate regions, to graze
undisturbed on these luxuriant pastures §. The rein-deer
often pass along in the same manner, by the chain of the Aleu-
tian Islands, from Behring's Straits to Kamtschatka, subsist-
ing on the moss found in these islands during their passage ||.

Within the tropics there are no ice-floes ; but, as if to com-
pensate for that mode of transportation, there are floating isles
of matted trees, which are often borne along through consider-
able spaces. These are sometimes seen sailing at the dis-
tance of fifty or one hundred miles from the mouth of the

* Append, to Parry's Second Voyage, years 1819-20.
t Account of the Arctic Regions, vol. i. p. 518.
% Turton, in a note to Goldsmith's Nat. Hist., vol. iii. p. 43.
§ Supplement to Parry's First Voyage of Disc, p, 189.
|| Godman's American Nat. Hist., vol, i. p. 22.
Vol. II. II

DRIFTING OF ANIMALS

[Ch. VI.

Ganges, with living trees standing erect upon them. The
Amazon, the Congo, and 'the Orinoco, also produce these ver-
dant rafts, which are formed in the manner already described
when speaking of the great raft of the Atchafalaya, an arm of
the Mississippi, where a natural bridge of timber, ten miles
long, and more than two hundred yards wide, has existed for
more than forty years, supporting a luxurious vegetation, and
rising and sinking with the water which flows beneath it *. That
this enormous mass will one day break up and send down a mul-
titude of floating islands to the gulf of Mexico, is the hope and
well-founded expectation of the inhabitants of Louisiana.

On these green isles of the Mississippi, observes Malte-Brunf,
young trees take root, and the pisliar and nenuphar display
their yellow flowers ; there serpents, birds, and the cayman
alligator, come to repose, and all are sometimes carried to the
sea, and engulphed in its waters.

In a memoir lately published, a naval officer informs us, that
as he returned from China by the eastern passage, he fell in,
among the Moluccas, with several small floating islands of
this kind, covered with mangrove-trees interwoven with under-
wood. The trees and shrubs retained their verdure, receiving
nourishment from a stratum of soil which formed a white beach
round the margin of each raft, where it was exposed to the
washing of the waves and the rays of the sun | t The occurrence
of soil in such situations may easily be explained, for all the natu-
ral bridges of timber which occasionally connect the islands of
the Ganges, Mississippi, and other rivers, with their banks, are
exposed to floods of water, densely charged with sediment.

Captain W. H. Smyth informs me, that when cruizing in
the Cornwallis amidst the Philippine Islands, he has more
than once seen, after those dreadful hurricanes called typhoons,
floating islands of wood, with trees growing upon them, and
that ships have sometimes been in imminent peril, in conse-
quence of mistaking them for terra-firma.

* See ante, vol. i. p. 188. f System of Geography, vol.'v, p. 157.

t United Service Journal, No. 24, p. 697.

Ch. VI.]

ON FLOATING ISLANDS.

It is highly interesting to trace, in imagination, the effects
of the passage of these rafts from the mouth of a large river to
some archipelago, such as those in the South Pacific, raised
from the deep, in comparatively modern times, by the opera-
tions of the volcano and the earthquake, and the joint labours
of coral animals and testacea. If a storm arise, and the frail
vessel be wrecked, still many a bird and insect may succeed in
gaining, by flight, some island of the newly-formed group,
while the seeds and berries of herbs and shrubs, which fall into
the waves, may be thrown upon the strand. But if the surface
of the deep be calm, and the rafts are carried along by a cur-
rent, or wafted by some slight breath of air fanning the foliage
of the green trees, it may arrive, after a passage of several
weeks, at the bay of an island, into which its plants and animals
may be poured out as from an ark, and thus a colony of
several hundred new species may at once be naturalized.

We may remind the reader, that we merely advert to the
transportation of these rafts as of extremely rare and accidental
occurrence; but it may account, in tropical countries, for some
of the rare exceptions to the general law, of the confined range
of species.

Many of the cetacea, the whales of the northern seas for
example, are found to desert one tract of the sea, and to visit
another very distant, when they are urged by want of food or
danger. The seals also retire from the coasts of Greenland in
July, return again in September, and depart again in March,
to return in June. They proceed in great droves northwards,
directing their course where the sea is most free from ice, and
are observed to be extremely fat when they set out on this
expedition, and very lean when they come home again # .

Some naturalists have wondered that the sea-calves, dolphins,
and other marine mammalia of the Mediterranean and Euxine
should be identical with those found in the Caspian ; and
among other fanciful theories, they have suggested that they
may dive through subterranean conduits, and thus pass from

* Krantz, vol. i. p. 129, cited by Goldsmith, Nat. Hist., vol. iii. p. 260,

II 2

100

HABITATIONS OF BIRDS.

[Ch. VI.

one sea into the other. But as the occurrence of wolves and
other noxious animals, on both sides the British channel, was
adduced by Desmarest, as one of many arguments to prove that
England and France were once united, so the correspondence
of the aquatic species of the inland seas of Asia with those of
the Black Sea, tends to confirm the hypothesis for which there
are abundance of independent geological data, that those seas
were connected together by straits at no remote period of the
earth's history.

Geographical Distribution and Migrations of Birds.

We shall now offer a few observations on some of the other
divisions of the animal kingdom. Birds, notwithstanding their
great locomotive powers, form no exception to the general rules
already laid down, but, in this class as in plants and terrestrial
quadrupeds, different groups of species are circumscribed
within definite limits. We find, for example, one assemblage
in the Brazils, another in the same latitudes in central Africa,
another in India, and a fourth in New Holland. But some
species again are so local, that in the same archipelago, a single
island frequently contains a species found in no other spot on
the whole earth ; as is exemplified in some of the parrot tribes.
In this extensive family, which are, with few exceptions, in-
habitants of tropical regions, the American group has not one
in common with the African, nor either of these with the par-
rots of India*.

Another illustration is afforded by that minute and beautiful
tribe, the humming-birds. The whole of them are, in the
first place, peculiar to the new world ; but there, although
some have a considerable range, as the Trochilus flammifrons
which is common to Lima, the island of Juan Fernandez and the
Straits of Magellan f, other species are peculiar to some of

* Prichard, vol. i. p. 47.

f Captain King, during his late survey, found this bird at the Straits of Magel-
lan, in the month of May, the depth of winter, sucking the flowers of the large
species of fuchsia, then in bloom in the midst of a shower of snow.

.Ch. VI.]

THEIR POWERS OF DIFFUSION.

101

the West-India islands, and have not been found elsewhere in
the western hemisphere. The ornithology of our own country
affords a no less striking exemplification of the same law, for
the common grouse (Tetrao scoticus) occurs nowhere in the
known world except in the British isles.

Some species of the vulture tribe are said to be true cos-
mopolites, and the common wild goose, Anas anser, Linn., if
we may believe some ornithologists, is a general inhabitant
of the globe, being met with from Lapland to the Cape of
Good Hope, frequent in Arabia, Persia, China, and Japan,
and in the American continent, from Hudson's Bay to South
Carolina *. An extraordinary range has also been attributed
to the nightingale, which extends from western Europe to
Persia, and still farther. In a work entitled Specchio Compa-
rative "ft by Charles Bonaparte, many species of birds are
enumerated as common to Rome and Philadelphia; the
greater part of these are migratory, but some of them, such
as the long-eared owl, Strix otus, are permanent in both
countries.

In parallel zones of the northern and southern hemispheres,
a great general correspondence of form is observable, both in
the aquatic and terrestrial birds, but there is rarely any
specific identity ; and this phenomenon is truly remarkable,
when we recollect the readiness with which some birds, not
gifted with great powers of flight, shift their quarters to dif-
ferent regions, and the facility with which others, possessing
great strength of wing, perform their aerial voyages. Some
migrate periodically from high latitudes, to avoid the cold of
winter, and the accompaniments of cold, — scarcity of insects
and vegetable food ; others, it is said, for some particular
kinds of nutriment required for rearing their young : for this
purpose, they often traverse the ocean for thousands of miles,
and re-cross it at other periods, with equal security.

Periodical migrations, no less regular, are mentioned by

* Bewick's Birds, vol. ii. p. 294, who cites Latham,
t Pisa, 1827 (not sold).

102

MIGRATIONS OF BIRDS.

[Ch. VI.

Humboldt, of many American water-fowl, from one part of
the tropics to another in a zone where there is the same tem-
perature throughout the year. Immense flights of ducks leave
the valley of the Orinoco, when the increasing depth of its
waters and the flooding of its shores prevent them from catch-
ing fish, insects, and aquatic worms. They then betake them-
selves to the Rio Negro and Amazon, having passed from the
eighth and third degrees of north latitude, to the first and
fourth of south latitude, directing their course south south-
east. In September, when the Orinoco decreases and re-enters
into its channel, these birds return northwards *.

The insectivorous swallows which visit our island Avould
perish during winter, if they did not annually repair to warmer
climes. It is supposed, that in these aerial excursions the
average rapidity of their flight is not less than fifty miles an
hour, so that when aided by the wind they soon reach warmer
latitudes. Spallanzani calculated that the swallow can fly
at the rate of ninety-two miles an hour, and conceived that
the rapidity of the swift might be three times greater f. The
rate of flight of the eider-duck {Anas mollis sima) has been
ascertained to be ninety miles an hour ; and that of hawks
and several other tribes, to be one hundred and fifty miles.

When we reflect how easily different species, in a great lapse
of ages, may be each overtaken by gales and hurricanes, and,
abandoning themselves to the tempest, be scattered at random
through various regions of the earth's surface, where the tem-
perature of the atmosphere, the vegetation, and the animal
productions, might be suited to their wants, we shall be pre-
pared to find some species capriciously distributed, and to be
sometimes unable to determine the native countries of each.
Captain Smyth informs me, that when engaged in his survey
of the Mediterranean, he encountered a gale in the gulf of
Lyons, at the distance of between twenty and thirty leagues
from the coast of France, which bore along many land birds

* Voyage aux Regions Equinoxiales, tome vii. p. 429.
f Fleming, Phil, Zool., vol. ii, p. 43.

Ch. VI.] GEOGRAPHICAL DISTRIBUTION OF REPTILES.

103

of various species, some of which alighted on the ship, while
others were thrown with violence against the sails. In this
manner islands become tenanted by species of birds inhabiting
the nearest main land.

Geographical Distribution and Dissemination of Rejrfiles.

A few facts respecting the third great class of vertebrated
animals, will suffice to show that the plan of nature, in regard
to their location on the globe, is perfectly analogous to that
already exemplified in other parts of the organic creation, and
has probably been determined by similar causes.

Of the great saurians, the gavials which inhabit the Ganges
differ from the cayman of America, or the crocodile of the
Nile. The monitor of New Holland is specifically distinct from
the Indian species ; these latter again from the African, and
all from their congeners in the new world. So in regard to
snakes ; we find the boa of America, represented by the python,
a different though nearly allied genus, in India. America is
the country of the rattle-snake, Africa of the cerastes, and Asia
of the hooded snake or cobra di capello. There is a legend
that St. Patrick expelled all reptiles from Ireland, and certain
it is that none of the three species of snakes common in Eng-
land, nor the toad, have been observed there by naturalists.
They have our common frog, and our water-newt, and accord-
ing to Ray (Quad. 264.) the green lizard (Lacerta viridis).
Schultes the botanist observed, a few years since, in his tour in
England, that there were two great islands in Europe of which
the floras were unknown, Sardinia and Ireland ; we believe he
might also have added the fauna of the latter country.

The range of the large reptiles is, in general, quite as limited
as that of some orders of the terrestrial mammalia. The great
saurians sometimes cross a considerable tract, in order to pass
from one river to another ; but their motions by land are gene-
rally slower than those of quadrupeds. By water, however,
they may transport themselves to distant situations more easilv.
The larger alligator of the Ganges sometimes descends beyond
the brackish water of the Delta into the sea, and in such cases

104

DISSEMINATION OF REPTILES.

[Ch.VI.

it might chance to be drifted away by a current, and survive
till it reached a shore at some distance ; but such casualties are
probably very rare # .

Turtles migrate in large droves from one part of the ocean to
another during the ovipositing season. Dr. Fleming f mentions
that an individual of the hawk's bill turtle (Chelonia imbricata)
so common in the American seas has been taken at Papa Stour,
one of the West Zetland islands ; and according to Sibbald,
" the same animal came into Orkney." Another was taken in
1774, in the Severn, according to Turton. Two instances also of
the occurrence of the leathern tortoise (C coriacea), on the coast
of Cornwall, in 1756, are mentioned by Borlase. These animals
of more southern seas can only be considered as stragglers
attracted to our shores during uncommonly warm seasons by an
abundant supply of food, or driven by storms to high latitudes.

Some of the smaller reptiles lay their eggs on aquatic plants;
and these must often be borne rapidly by rivers, and conveyed
to distant regions, in a manner similar to the dispersion of
seeds before adverted to. But that the larger ophidians may be
themselves transported across the seas is evident from the fol-
lowing most interesting account of the arrival of one at the
island of St. Vincent. It is worthy of being recorded, says the
Rev. L. Guilding;};, " that a noble specimen of the Boa con-
strictor was lately conveyed to us by the currents, twisted
round the trunk of a large sound cedar tree, which had pro-
bably been washed out of the bank by the floods of some great
South American river, while its huge folds hung on the
branches, as it waited for its prey. The monster was fortu-
nately destroyed after killing a few sheep, and his skeleton
now hangs before me in my study, putting me in mind how
much reason I might have had to fear in my future rambles
through the forests of St. Vincent, had this formidable reptile
been a pregnant female, and escaped to a safe retreat."

* Malte-Brun says (Syst.of Geog. vol. viii. p, 193), that a crocodile is still pre-
served at Lyons that was taken from the Rhone, ahout two centuries ago; but no
particulars are given. f Brit. Animals, p. 149 ; who cites Sibbald.

% Zool. Journ. vol. iii. p. 406. Dec. 1827.

CHAPTER VII.

Geographical distribution and migrations of fish — of testacea — Causes which
limit the extension of many species — Their mode of diffusion — Geographical
range of zoophytes — Their powers of dissemination — Distribution of insects —
Migratory instincts of some species — Certain types characterize particular
countries — Their means of dissemination — Geographical distribution and
diffusion of man — Speculations as to the birth-place of the human species —
Progress of human population — Drifting of canoes to vast distances — On the
involuntary influence of man in extending the range of many other species.

Geographical Distribution and Migrations of Fish.

Although we are less acquainted with the habitations of
marine animals than with the grouping of the terrestrial species
before described, yet it is well ascertained that their distribu-
tion is governed by the same general laws. The testimony
borne by MM. Peron and Lesueur to this important fact is
remarkably strong. These eminent naturalists, after collect-
ing and describing many thousand species which they brought
to Europe from the southern hemisphere, insist most emphati-
cally on their distinctness from those north of the equator ; and
this remark they extend to animals of all classes, from those of a
more simple to those of a more complex organization, from the
sponges and medusae to the cetacea. " Among all those which
we have been able to examine," say they, " with our own
eyes, or with regard to which it has appeared to us possible to
pronounce with certainty, there is not a single animal of the
southern regions which is not distinguished by essential cha-
racters from the analogous species in the northern seas *

The fish of the Arabian gulf are said to differ entirely from

* Sur les Habitations des Animaux Marins. Ann. du Mus. torn, xv., cited by
Prichard, Phys. Hist, of Mankind, vol. i.p. 51.

106

MIGRATIONS OF FISH.

[Ch. VII.

those of the Mediterranean, notwithstanding the proximity of
these seas. The flying-fish are found (some stragglers ex-
cepted) only between the tropics, — in receding from the line
they never approach a higher latitude than the fortieth parallel.
Those inhabiting the Atlantic are said to be different species
from those of the eastern ocean # . The electric gymnotus
belongs exclusively to America, the trembler, or Sihirus elec-
tricus to the rivers of Africa ; but the torpedo, or crampfish,
is said to be dispersed over all tropical and many temperate
seasf.

All are aware that there are certain fish of passage which
have their periodical migrations like some tribes of birds. The
salmon, towards the season of spawning, ascends the rivers for
hundreds of miles, leaping up the cataracts which it meets in
its course, and then retreats again into the depths of the ocean.
The herring and the haddock, after frequenting certain shores
in vast shoals for a series of years, desert them again and resort
to other stations, followed by the species which prey on them.
Eels are said to descend into the sea for the purpose of pro-
ducing their young, which are seen returning into the fresh-
water by myriads, extremely small in size, but possessing the
power of surmounting every obstacle which occurs in the course
of a river, by applying their slimy and glutinous bodies to the
surface of rocks, or the gates of a lock, even when dry, and so
climbing over it £.

Gmelin says, that the anseres subsist in their migrations on
the spawn of fish, and that oftentimes when they void the
spawn, two or three days afterwards, the eggs retain their vitality
unimpaired §. When there are many disconnected freshwater-
lakes in a mountainous region, at various elevations, each
remote from the other, it has often been deemed inconceivable
how they could all become stocked with fish from one common
source ; but it has been suggested, that the minute eggs of

* Malte-Brun, vol.i. p. 507.
+ Phil. Trans. 1747, p. 395,

t Ibid.
§ Amo3n, Acad., Essay 75,

Ch. VII.]

MIGRATIONS OF FISH.

107

these animals may sometimes be entangled in the feathers of
water-fowl. These, when they alight to wash and plume
themselves in the water, may often unconsciously contribute
to propagate swarms of fish, which, in due season, will supply
them with food. Some of the water-beetles, also, as the dy-
ticidse, are amphibious, and in the evening quit their lakes
and pools, and flying in the air transport the minute ova of
fishes to distant waters. In this manner some naturalists
account for the fry of fish appearing occasionally in small pools
caused by heavy rains.

Geographical Distribution and Migrations of Tesfacea.

The testacea, of which so great a variety of species occurs in
the sea, are a class of animals of peculiar importance to the
geologist, because their remains are found in strata of all ages,
and generally in a higher state of preservation than those of
other organic beings. Climate has a decided influence on the
geographical distribution of species in this class ; but as there
is much greater uniformity of temperature in the waters of the
ocean, than in the atmosphere which invests the land, the
diffusion of many marine molluscs is extensive.

Some forms, as those of the nautili, volutse, and cyprBeee,
attain their fullest development in warm latitudes ; and most
of their species are exclusively confined to them. Peron and
Lesueur remark, that the Haliotis gigantea, of Van Dieman's
land, and the Phasianella, diminish in size as they follow the
coasts of New Holland to King George's straits, and entirely
disappear beyond them *. Almost all the species of South
American shells differ from those of the Indian archipelago in
the same latitudes ; and on the shores of many of the isles of
the South Pacific, peculiar species have been obtained. But
we are as yet by no means able to sketch out the submarine
provinces of shells, as the botanist has done those of the terres-
trial, and even of the subaqueous plants. There can be little

* Ami, duMus. d'Hist, Nat., torn, xv,

108

GEOGRAPHICAL DISTRIBUTION AND

[ch. vir.

doubt, however, that the boundaries in this case, both of lati-
tude and longitude, will be found in general well defined. The
continuous lines of continents^ stretching from north to south,
prevent a particular species from belting the globe, and follow-
ing the direction of the isothermal lines. The inhabitants of
the West Indian seas, for example, cannot enter the Pacific
without passing round through the inclement climate of Cape
Horn.

Currents also flowing permanently in certain directions, and
the influx at certain points of great bodies of fresh- water, limit
the extension of many species. Those which love deep water
are arrested by shoals ; others, fitted for shallow seas, cannot
migrate across unfathomable abysses. Some few species, how-
everj have an immense range, as the Bulla aperta for example,
which is found in almost all zones. The habitation of the
Bulla striata extends from the shores of Egypt to the coasts of
England and France, and it recurs again in the seas of Senegal,
Brazil, and the West Indies. The Turbo petrasus inhabits the
seas of England, Guadaloupe, and the Cape of Good Hope *,
and many instances of a similar kind might be enumerated.
The Ianthina fragilis has wandered into almost every sea
both tropical and temperate. This " common oceanic snail"
derives its buoyancy from an admirably contrived float, which
has enabled it not only to disperse itself so universally, but to
become an active agent in disseminating other species which
attach themselves, or their ova, to its shell f.

It is evident that among the testacea, as in plants and the
higher orders of animals, there are species which have a power
of enduring a wide range of temperature, whereas others can-
not resist a considerable change of climate. Among the fresh-

* Fer. Art. Geogr. Phys. Diet. Class. d'Hist. Nat,

f Mr. Broderip possesses specimens of Ianthina fragilis, bearing more than one
species of barnacle (Pentelasmis), presented to him by Captain King and Lieu-
tenant Graves. One of these specimens, taken alive by Captain King far at sea,
and a little north of the equator, is so loaded with those cirrhipeds, and with
numerous ova, that all the upper part of its shell is invisible.

Ch.VII.]

MIGRATIONS OF TESTACEA,

109

water molluscs, and those which breathe air, Ferrussac
mentions a few instances of species of almost universal dif-
fusion*

The Helix putris (Succinea putris, Lam.) so common in
Europe, where it reaches from Norway to Italy, is also found
in Egypt, in the United States, in Newfoundland, Jamaica,
Tranquebar, and, it is even said, in the Marianne Isles. As
this animal inhabits constantly the borders of pools and streams
where there is much moisture, it is not impossible that different
water-fowl have been the agents of spreading some of its
minute eggs, which may have been entangled in their feathers.
Helix aspersa, one of the commonest of our larger land-shells,
is found in South America, at the foot of Chimborazo, as also
in Cayenne. Some conchologists have conjectured, that it was
accidentally imported in some ship ; for it is an eatable species,
and these animals are capable of retaining life, during long
voyages, without air or nourishment # .

Mr. Lowe, in a memoir just published in the Cambridge
Transactions, enumerates seventy-one species of land mollusca,
collected by him in the islands of Madeira and Porto Santo,
sixty of which belonged to the genus Helix alone, including
as subgenera Bulimus and Achatina, and excluding Vitrina
and Clausilia ; — forty-four of these are new. It is remarkable,
that very few of the above-mentioned species are common
to the neighbouring archipelago of the Canaries ; but it is a
still more striking fact, that of the sixty species of the three
genera above-mentioned, thirty-one are natives of Porto Santo ;
whereas, in Madeira, which contains ten times the superficies,
were found but twenty -nine. Of these only four were common

* Four individuals of a large species of Bulimus, from Valparaiso, were
brought to England by Lieutenant Graves, who accompanied Captain King in
his late expedition to the Straits of Magellan. They had been packed up in a
box and enveloped in cotton, two for a space of thirteen, one for seventeen, and
a fourth for upwards of twenty months ; but on being exposed, by Mr. Broderip,
to the warmth of a fire in London, and provided with tepid water and leaves,
they revived, and are now living inMr. Loddiges' palm-house.

110

GEOGRAPHICAL DISTRIBUTION OF TESTACEA.

[Ch. VII.

to the two islands, which are only separated by a distance
of twelve leagues ; and two even of these four (namely,
Helix rhodostoma and H. ventrosa) are species of general dif-
fusion, common to Madeira, the Canaries, and the South of
Europe*.

The confined range of these molluscs may easily be explained,
if we admit that species have only one birth-place ; and the
only problem to be solved would relate to the exceptions — to
account for the dissemination of some species throughout
several isles and the European continent. May not the eggs,
when washed into the sea by the undermining of cliffs, float
uninjured to a distant shore ?

Notwithstanding the proverbially slow motion of snails and
molluscs in general, and although many aquatic species adhere
constantly to the same rock for their whole lives, they are by
no means destitute of provision for disseminating themselves
rapidly over a wide area. Some lay their eggs in a sponge-like
nidus, wherein the young remain enveloped for a time after
their birth, and this buoyant substance floats far and wide as
readily as sea-weed. The young of other viviparous tribes are
often borne along, entangled in sea-weed. Sometimes they are
so light that, like grains of sand, they can be easily moved by
currents. Balani and serpulse are sometimes found adhering to
floating cocoa-nuts, and even to fragments of pumice. In rivers
and lakes, on the other hand, aquatic univalves usually attach
their eggs to leaves and sticks which have fallen into the water,
and which are liable to be swept away, during floods, from
tributaries to the main streams, and from thence to all parts
of the same basins. Particular species may thus migrate
during one season from the head waters of the Mississippi,
or any other great river, to countries bordering the sea, at the
distance of many thousand miles.

An illustration of the mode of attachment of these eggs will
be seen in the annexed diagram. (No. 1.)

* Camb. Phil. Trans, vol. iv. 183],

Ch. VII.]

DISTRIBUTION OF ZOOPHYTES.

Ill

Eggs of fresh-mater Molluscs.

Fig. 1. Eggs of Ampullaria ovata (a fluviatile species), fixed to a small sprig which

had fallen into the water.
Fig. 2. Eggs of Planorhis albus, attached to a dead leaf lying under water.
Fig. 3. Eggs of the common Limneus (L. vulgaris), adhering to a dry stick under

water.

The habit of some testacea to adhere to floating wood is
proved by their fixing themselves to the bottoms of ships. By
this mode of conveyance Mytilus polymorphic has been
brought from northern Europe to the Commercial Docks in
the Thames, where the species is now domiciled.

Geographical Distribution and Migrations of Zoophytes.

Zoophytes are very imperfectly known, but there can be
little doubt that each maritime region possesses species pecu-
liar to itself. The madrepores, or lamelliferous polyparia, are
found in their fullest development only in the tropical seas of
Polynesia and the East and West Indies, and this family is
represented only by a few species in our seas. Those even of
the Mediterranean are inferior in size, and, for the most part,
different from such as inhabit the tropics. Peron andLesueur,

112 GEOGRAPHICAL DISTRIBUTION AND [Ch. VII.

after studying the Holothurise, Medusee, and other congeners
of delicate and changeable forms, came to the conclusion that
each kind has its place of residence determined by the tem-
perature necessary to support its existence. Thus, for ex-
ample, they found the abode of Pyrosoma Atlantica to be
confined to one particular region of the Atlantic ocean *.

Let us now inquire how the transportation of polyps from
one part of the globe to another is effected. Many of them,
as in the families Flustra and Sertularia, attach themselves to
sea-weed, and are occasionally drifted along with it. Many
fix themselves to the shells of gasteropods, and are thus borne
along by them to short distances. Some polyps, like the sea-
pens, swim freely about in the sea. But the most frequent
mode of transportation, probably, consists in the buoyancy of
their eggs, or certain small vesicles which are detached and
are capable of becoming the foundation of a new colony. These
gems, as they have been called, may be swept along by a wave
that breaks upon a coral-reef, and may then be borne by a
current to a distance.

That some zoophytes adhere to floating bodies is proved by
their being found attached to the bottoms of ships, as in the
case of testacea before alluded to.

Geographical Distribution and Migrations of Insects.

Before we conclude our sketch of the manner in which the
habitable parts of the earth are shared out among particular
assemblages of organic beings, we must offer a few remarks
on insects, which, by their numbers, and the variety of their
powers and instincts, exert a prodigious influence in the eco-
nomy of animate nature. As a large portion of these minute
creatures are strictly dependent for their subsistence on certain
species of vegetables, the entomological provinces must coin-
cide in a considerable degree with the botanical.

All the insects, says Latreille, brought from the eastern parts

* Voy. aux Terres Australes, tome i. p. 492.

Ch. VII.]

MIGRATIONS OF INSECTS.

113

of Asia and China, whatever be their latitude and tempera-
ture, are distinct from those of Europe and of Africa. The
insects of the United States, although often they approach
very close to our own, are nevertheless specifically distinguish-
able by some characters. In South America, the equinoctial
lands of New Grenada and Peru on the one side, and of Guiana
on the other, contain for the most part distinct groups ; the
Andes forming the division, and interposing a narrow line
of severe cold between climates otherwise very similar*.

The insects of the United States, even those of the northern
provinces as far as Canada, differ specifically from the Euro-
pean, while those of Greenland appear to be in a great measure
identical with our own. Some insects are very local, while
a few, on the contrary, are common to remote countries, be-
tween which the torrid zone and the ocean intervene. Thus
our painted lady butterfly ( Vanessa Carclui) reappears in New
Holland and Japan with scarcely a varying streak f . The
same species is said to be one of the few insects which are
universally dispersed over the earth, being found in Europe,
Asia, Africa, and America ; and its wide range is the more
interesting because it seems explained by its migratory instinct,
seconded, no doubt, by a capacity enjoyed by few species, of
enduring a great diversity of temperature.

A vast swarm of this species, forming a column from ten to
fifteen feet broad, was, a few years since, observed in the
Canton de Vaud ; they traversed the country with great
rapidity from north to south, all flying onwards in regular
order, close together, and not turning from their course on
the approach of other objects. Professor Bonelli, of Turin,
observed, in March of the same year, a similar swarm of the
same species, also directing their flight from north to south, in
Piedmont, in such immense numbers, that at night the flowers
were literally covered with them. They had been traced from

* Geographic Generate des Insectes et des Arachnides. Mem. du Mus. d'Hist
Nat. tome iii.

f Kirby and Spence, vol. iv. p. 487.

Vol. II. I

114' GEOGRAPHICAL DISTRIBUTION AND [Ch. VII.

Coni, Raconi, Susa, &c. A similar flight at the end of the
last century is recorded by M. Louch, in the Memoirs of the
Academy of Turin. The fact is the more worthy of notice,
because the caterpillars of this butterfly are not gregarious, but
solitary from the moment that they are hatched ; and this
instinct remains dormant, while generation after generation
passes away, till it suddenly displays itself in full energy when
their numbers happen to be in excess.

Not only peculiar species but certain types distinguish
particular countries ; and there are groups, observes Kirby,
which represent each other in distant regions, whether in their
form, their functions, or in both. Thus the honey and wax of
Europe, Asia, and Africa, are in each case prepared by bees
congenerous with our common hive-bee {Apis, Latr.) ; while in
America, this genus is nowhere indigenous, but is replaced
by Melipona and Trigona ; and in New Holland by a still
different, but undescribed type *.

As almost all insects are winged, they can readily spread
themselves wherever their progress is not opposed by un-
congenial climates, or by seas, mountains, and other phy-
sical impediments ; and these barriers they can sometimes sur-
mount by abandoning themselves to violent winds, which, as
we before stated, when speaking of floating seeds, may in a
few hours carry them to very considerable distances. On the
Andes some sphinxes and flies have been observed by Hum-
boldt, at the height of nineteen thousand one hundred and
eighty feet above the sea, and which appeared to him to have
been involuntarily carried into these regions by ascending
currents of air f .

White mentions a remarkable shower of aphides which
seem to have emigrated, with an east wind, from the great hop
plantations of Kent and Sussex, and blackened the shrubs and
vegetables where they alighted at Selbourne, spreading at the
same time in great clouds all along the vale from Farnham. to

* Kirby and Spence, vol. iv. p. 497.
f Description of the Equatorial Regions^Malte-Brun, vol. v. p. 379.

Ch. VII.]

MIGRATIONS OF INSECTS.

115

Alton. These aphides are sometimes accompanied by vast
numbers of the common lady-bird (Coccinella semptem-punc-
tata), which feed upon them *.

It is remarkable, says Kirby, that many of the insects which
are occasionally observed to emigrate, as, for instance, the
libellulae, coccinellas, carabi, cicadas, &c, are not usually social
insects, but seem to congregate, like swallows, merely for the
purpose of emigration f . Here, therefore, we have an example
of an instinct developing itself on certain rare emergencies,
causing unsocial species to become gregarious, and to venture
sometimes even to cross the ocean.

To the armies of locusts darkening the air in Africa, and
traversing the globe from Turkey to our southern counties in
England, we need not here allude. When the western gales
sweep over the Pampas, they bear along with them myriads
of insects of various kinds. As a proof of the manner in which
species may be thus diffused, we may mention that when the
Creole frigate was lying in the outer roads off Buenos Ayres,
in 1819, at the distance of six miles from the land, her decks
and rigging were suddenly covered with thousands of flies and
grains of sand. The sides of the vessel had just received a
fresh coat of paint, to which the insects adhered in such num-
bers as to spot and disfigure the vessel, and to render it neces-
sary partially to renew the paint %. Captain W. H. Smyth
was obliged to repaint his vessel, the Adventure, in the Medi-
terranean, from the same cause. He was on his way from
Malta to Tripoli^ when a southern wind blowing from the
coast of Africa, then one hundred miles distant, drove such
myriads of flies upon the fresh paint, that not the smallest point
was left unoccupied by insects.

To the southward of the river Plate, off Cape St. An-
tonio, and at the distance of fifty miles from land, several
large dragon-flies alighted on the Adventure frigate, during
Captain King's late expedition to the Straits of Magellan. If

* Kirby and Spence, vol. ii. p. 9, 1817. f Vol. ii. p. 12.

J I am indebted to Lieutenant Graves, R,N. for this information.

I 2

116

GEOGRAPHICAL DISTRIBUTION AND [Ch. VIl*

the wind abates when insects are thus crossing the sea, the
most delicate species are not necessarily drowned, for many
can repose without sinking on the unruffled surface of the
deep. The slender, long-legged tipulae have been seen stand-
ing on the surface of the sea, when driven out far from our
coast, and took wing immediately on being approached *.
Exotic beetles are sometimes thrown on our shore, which revive
after having been long drenched in salt-water ; and the peri-
odical appearance of some conspicuous butterflies amongst us,
after being unseen for five or fifty years, has been ascribed, not
without probability, to the agency of the winds.

Inundations of rivers, observes Kirby, if they happen at any
season except in the depth of winter, always carry down a,
number of insects, floating on the surface of bits of stick,
weeds, &c, so that when the waters subside, the entomologist
may generally reap a plentiful harvest. In the dissemination,
moreover, of these minute beings, as in that of plants, the
larger animals play their part. Insects are, in numberless
instances, borne along in the coats of animals, or the feathers of
birds ; and the eggs of some species are capable, like seeds, of
resisting the digestive powers of the stomach, and after they
are swallowed with herbage, may be ejected again unharmed in
the dung.

Geographical Distribution and Diffusion of Man.

We have reserved for the last our observations on the range
and diffusion of the human species over the earth, and the in-
fluence of man, in spreading other animals and plants, espe-
cially the terrestrial,

Many naturalists have amused themselves in speculating on
the probable birth-place of mankind, the point from which,
if we assume the whole human race to have descended from a
single pair, the tide of emigration must originally have pro-
ceeded. It has been always a favourite conjecture, that this
birth-place was situated within or near the tropics, where per-

* I state this fact on the authority of my friend, Mr. Curtis.

Ch. VII.]

DIFFUSION OF MAN.

117

petual summer reigns, and where fruits, herbs, and roots, are
plentifully supplied throughout the year. The climate of
these regions, it has been said, is suited to a being born without
any covering, and who had not yet acquired the arts of build-
ing habitations or providing clothes.

" The hunter state," it has been argued, <f which Montes-
quieu placed the first, was probably only the second stage to
which mankind arrived, since so many arts must have been
invented to catch a salmon or a deer, that society could no
longer have been in its infancy when they came into use *."
When regions where the spontaneous fruits of the earth abound
became overpeopled, men would naturally diffuse themselves
over the neighbouring parts of the temperate zone ; but a con-
siderable time would probably elapse before this event took
place ; and it is possible, as a writer before cited observes, that
in the interval before the multiplication of their numbers and
their increasing wants had compelled them to emigrate, some
arts to take animals were invented^ but far inferior to what we
see practised at this day among savages. As their habitations
gradually advanced into the temperate zone, the new diffi-
culties they had to encounter would call forth by degrees the
spirit of invention, and the probability of such inventions
always rises with the number of people involved in the same
necessity -\.

A distinguished modern writer, who coincides for the most
part in the views of Aphonin above mentioned, has introduced
one of the persons in his second dialogue as objecting to the
theory of the human race having gradually advanced from a
savage to a civilized state, on the ground that ci the first man
must have inevitably been destroyed by the elements or de-
voured by savage beasts, so infinitely his superiors in physical
force |. M He then contends against the difficulty here started

* Rev. J. F. Brand, commenting on Aphonin, Amoeu. Acad. vol. vii. p. 409.
Brand's Select Dissert, from the Amoen. Acad. vol. i. p. 118.

t Idem., ib.
I Sir H. Davy, Consolations in Travel, p. 74.

118

GEOGRAPHICAL DISTRIBUTION AND

[Ch. VII.

by various arguments, all of which were, perhaps, superfluous,
for if a philosopher is pleased to indulge in conjectures on this
subject, why should he not assign, as the original seat of man,
some one of those large islands within the tropics, which are as
free from wild beasts as Van Diemen's Land or Australia ? Here
man may have remained for a period peculiar to a single isle,
just as some of the large anthropomorphous species are now
limited to one island within the tropics. In such a situa-
tion, the new-born race might have lived in security, though
far more helpless than the New Holland savages, and might
have found abundance of vegetable food. Colonies may after-
wards have been sent forth from this mother country, and then
the peopling of the earth may have proceeded according to
the hypothesis before alluded to.

In an early stage of society the necessity of hunting acts
as a principle of repulsion, causing men to spread with the
greatest rapidity over a country, until the whole is covered
with scattered settlements. It has been calculated that eight
hundred acres of hunting-ground only produce as much food
as half an acre of arable land. When the game has been in a
great measure exhausted, and a state of pasturage succeeds,
the several hunter tribes, being already scattered, may multiply
in a short time into the greatest number which the pastoral
state is capable of sustaining. The necessity, says Brand,
thus imposed upon the two savage states, of dispersing them-
selves far and wide over the country, affords a reason why, at
a very early period, the worst parts of the earth may have
become inhabited.

But this reason it may be said is only applicable in as far as
regards the peopling of a continuous continent ; whereas the
smallest islands, however remote from continents, have almost
invariably been found inhabited by man. St. Helena, it is
true, afforded an exception ; for when that island was dis-
covered in 1501, it was only inhabited by sea-fowl, and occa-
sionally by seals and turtles, and was covered with a forest of
trees and shrubs, all of species peculiar, as we before observed,

Ch. VII.]

DIFFUSION OF MAN.

119

with one or two exceptions, and which seem to have been
expressly created for this remote and insulated spot.

But very few of the numerous coral islets and volcanos of
the vast Pacific, capable of sustaining a few families of men,
have been found untenanted, and we have, therefore, to in-
quire whence and by what means, if all the members of the
great human family have had one common source, could those
savages have migrated. Cook, Forster, and others have re-
marked that parties of savages in their canoes must often
have lost their way and must have been driven on distant
shores, where they were forced to remain, deprived both
of the means and of the requisite intelligence for returning
to their own country. Thus Captain Cook found on the
island Wateoo, three inhabitants of Otaheite, who had been
drifted thither in a canoe, although the distance between the
two isles is five hundred and fifty miles. In 1696, two
canoes containing thirty persons, who had left Ancorso,
were thrown by contrary winds and storms on the island of
Samar, one of the Philippines, at a distance of eight hundred
miles. In 1721, two canoes, one of which contained twenty-
four, and the other six persons, men, women, and children,
were drifted from an island called Baroilep, to the island of
Guam, one of the Marians

Kotzebue, when investigating the Coral isles of Radack, at
the eastern extremity of the Caroline isles, became acquainted
with a person of the name of Kadu, who was a native of Ulea,
an isle fifteen hundred miles distant, from which he had been
drifted with a party. Kadu and three of his countrymen, one
day, left Ulea in a sailing boat, when a violent storm arose, and
drove them out of their course ; they drifted about the open
sea for eight months, according to their reckoning by the moon,
making a knot on a cord at every new moon. Being expert
fishermen they subsisted entirely on the produce of the sea ;
and when the rain fell, laid in as much fresh-water as they had
vessels to contain it. " Kadu," says Kotzebue, t( who was the

* Malte-Bran's Geography, vol. iii. p. 419.

120

DISTRIBUTION OF MAN.

[Ch. VII.

best diver, frequently went down to the bottom of the sea, where
it is well known that the water is not so salt, with a cocoa nut
shell, with only a small opening." When these unfortunate
men reached the isles of Radack, every hope and almost every
feeling had died within them ; their sail had long been de-
stroyed, their canoe had long been the sport of winds and waves s
and they were picked up by the inhabitants of Aur, in a state
of insensibility * ; but by the hospitable care of those islanders
they soon recovered, and were restored to perfect health.

Captain Beechey, in his late voyage to the Pacific, fell in
Avith some natives of the Coral Islands, who had in a similar
manner been carried to a great distance from their native
country. They had embarked to the number of one hundred
and fifty souls, in three double canoes, from Anaa, or Chain
Island, situate about three hundred miles to the eastward of
Otaheite. They were overtaken by the monsoon, which dis-
persed the canoes, and after driving them about the ocean, left
them becalmed, so that a great number of persons perished. Two
of the canoes were never heard of, but the other was drifted
from one uninhabited island to another, at each of which the
voyagers obtained a few provisions ; and at length, after
having wandered for a distance of six hundred miles, they
were found and carried to their home in the Blossom f.

The space traversed in some of these instances was so great,
that similar accidents might suffice to transport canoes from
various parts of Africa to the shores of South America, or
from Spain to the Azores, and thence to North America. So
that man, even in a rude state of society, is liable to be scattered
involuntarily by the winds and waves over the globe, in a
manner singularly analogous to that in which many plants and
animals are diffused. We ought not then to wonder that
during the ages required for some tribes of the human race to
attain that advanced stage of civilization which empowers the

* Kotzebue's Voyage, 1815 — 1818. Quarterly Review, vol. xxvi. p. 361.
t Narrative of a Voyage to the Pacific, &c, in the years 1825, 1826,1827,
1828, p. 170.

Ch. VII.] DISPERSION OF ANIMALS BY MAN. 121

navigator to cross the ocean in all directions with security, the
whole earth should have become the abode of rude tribes of
hunters and fishers. Were the whole of mankind now cut off,
with the exception of one family, inhabiting the old or new
continent, or Australia, or even some coral islet of the Pacific,
we should expect their descendants, though they should never
become more enlightened than the South Sea Islanders or the
Esquimaux, to spread in the course of ages over the whole
earth, diffused partly by the tendency of population to increase
beyond the means of subsistence, in a limited district, and
partly by the accidental drifting of canoes by tides and currents
to distant shores.

Involuntary influence of Man in diffusing Animals and

Plants.

Many of the general remarks which we made respecting the
influence of man in spreading or in checking the diffusion of
plants, apply equally to his relations with the animal kingdom.
We shall be led on a future occasion to speak of the instru-
mentality of our species in naturalizing useful animals and
plants in new regions, when we explain our views of the effects
which the spreading and increase of certain species exert in the
extirpation of others. At present we shall confine ourselves
to a few remarks on the involuntary aid which man lends to
the dissemination of species.

In the mammiferous class our influence is chiefly displayed
in increasing the number of quadrupeds which are serviceable
to us, and in exterminating or reducing the number of those
which are noxious.

Sometimes, however, we unintentionally promote the mul-
tiplication of inimical species, as when we introduced the rat,
which was not indigenous in the New World, into all parts of
America. They have been conveyed over in ships, and now
infest a great multitude of islands and parts of that continent.
In like manner the Norway rat has been imported into England,
where it plunders our property in ships and houses.

1%% DISPERSION OF ANIMALS BY MAN. [Ch. VII.

The great viper, fer de lance, a species no less venomous
than the rattle-snake, which now ravages Martinique and St.
Lucia, was accidentally introduced by man, and exists in no
other part of the West Indies.

Many parasitic insects, which attack our persons, and some
of which are supposed to be peculiar to our species, have been
carried into all parts of the earth, and have as high a claim as
man to an universal geographical distribution.

A great variety of insects have been transported in ships
from one country to another, especially in warmer latitudes.
Notwithstanding the coldness of our climate, we have been
unable to prevent the cockroach (Blatta orientalis), from
entering and diffusing itself in our ovens and kneading troughs,
and availing itself of the artificial warmth which we afford. It
is well known also that beetles, and many other kinds of ligni-
perdous insects, have been introduced into Great Britain in
timber; especially several North American species. 4 4 The
commercial relations," says Malte-Brun *, " between France
and India, have transported from the latter country the aphis,
which destroys the apple-tree, and two sorts of Neuroptera,
the lucifuga and flavicola, mostly confined to Provence and
the neighbourhood of Bordeaux, where they devour the timber
in the houses and naval arsenals."

Among molluscs we may mention the teredo navalis, which
is a native of equatorial seas, but which, by adhering to the
bottom of ships, was transported to Holland, where it has been
most destructive to vessels and piles. The same species has
also become naturalized in England, and other countries en-
joying an extensive commerce.

In all these and innumerable other instances, we may regard
the involuntary agency of man as strictly analogous to that of
the inferior animals. Like them we unconsciously contribute
to extend or limit the geographical range and numbers of cer-
tain species, in obedience to general rules in the economy of
nature, which are for the most part beyond our control.

* Syst. of Geog., Vol. viii. ; p. 169.

CHAPTER VIII.

Theories respecting the original introduction of species — Proposal of an hypo-
thesis on this subject — Supposed centres or foci of creation — Why the distinct
provinces of animals and plants have not become more blended together —
Brocchi's speculations on the loss of species — Stations of plants and animals
— Complication of causes on which they depend — Stations of plants, how
affected by animals — Equilibrium in the number of species, how preserved —
Peculiar efficacy of insects in this task — Rapidity with which certain insects
multiply, or decrease in numbers — Effect of omnivorous animals in preserving
the equilibrium of species — Reciprocal influence of aquatic and terrestrial

: species on each other.

It would be superfluous to examine the various attempts
which were made to explain the phenomena of the distribu-
tion of species alluded to in the preceding chapters, in the
infancy of the sciences of botany, zoology, and physical geo-
graphy. The theories or rather conjectures then indulged,
now stand refuted by a simple statement of facts ; and if Lin-
nasus were living, he would be the first to renounce the notions
which he promulgated. For he imagined the habitable world
to have been for a certain time limited to one small tract, the
only portion of the earth's surface that was as yet laid bare by
the subsidence of the primaeval ocean. In this fertile spot he
supposed the originals of all the species of plants which exist
on this globe to have been congregated^ together with the first
ancestors of all animals and of the human race. ,{ In qua com-
mode habitaverint animalia omnia, et vegetabilia laete germinave-
rint. 1 ' In order to accommodate the various habitudes of so
many creatures^ and to provide a diversity of climate suited to
their several natures, the tract in which the creation took
place was supposed to have been situated in some warm region
of the earthy but to have contained a lofty mountain range, on

the heights and in the declivities of which were to be found

124

THEORIES RESPECTING THE

[Ch. VIII.

all temperatures and every clime, from the torrid to the frozen
zone *.

That there never was a universal ocean since the planet was
inhabited, or rather since the oldest groups of strata yet
known to contain organic remains were formed, is proved by
the presence of terrestrial plants in all the older formations ;
and if this conclusion was not established, yet no geologist
could deny that since the first small portion of the earth was
laid dry, there have been many entire changes in the species
of plants and animals inhabiting the land.

But without dwelling on the above and other refuted theories,
let us inquire whether we can substitute some hypothesis as
simple as that of Linnaeus, to which the phenomena now
ascertained in regard to the distribution both of aquatic and
terrestrial species may be referred. The following may, per-
haps, be reconcileable with known facts : — Each species may
have had its origin in a single pair, or individual, where an in-
dividual was sufficient, and species may have been created in
succession at such times and in such places as to enable them
to multiply and endure for an appointed period, and occupy
an appointed space on the globe.

In order to explain this theory, let us suppose every living
thing to be destroyed in the western hemisphere, both on the
land and in the ocean, and permission to be given to man to
people this great desert, by transporting into it animals and
plants from the eastern hemisphere, a strict prohibition being
enforced against introducing two original stocks of the same
species.

Now the result we conceive of such a mode of colonizing
would correspond exactly, so far as regards the grouping of
animals and plants, with that now observed throughout the
globe. It would be necessary for naturalists, before they im-
ported species into particular localities, to study attentively the
climate and other physical conditions of each spot. It would

* De terra habitabili increment o ; also Prichard, Phys. Hist, of Mankind, vol. i.
p. 17, where the hypotheses of different naturalists are enumerated.

Ch. VIII.]

INTRODUCTION OF SPECIES.

125

be no less requisite to introduce the different species in suc-
cession, so that each plant and animal might have time and
opportunity to multiply before the species, destined to prey
upon it was admitted. Many herbs and shrubs, for example,
must spread far and wide before the sheep, the deer, and the
goat could be allowed to enter, lest they should devour and
annihilate the original stocks of many plants, and then perish
themselves for want of food. The above-mentioned herbi-
vorous animals in their turn must be permitted to make
considerable progress before the entrance of the first pair of
wolves or lions. Insects must be allowed to swarm before the
swallow could be permitted to skim through the air and feast
on thousands at one repast.-

It is evident that, however equally in this case our original
stocks were distributed over the whole surface of land and
water, there would nevertheless arise distinct botanical and
zoological provinces, for there are a great many natural barriers
which oppose common obstacles to the advance of a variety
of species. Thus, for example, almost all the animals and
plants naturalized by us towards the extremity of South
America, would be unable to spread beyond a certain limit,
towards the east, west, and south, because they would be
stopped by the ocean, and a few of them only would succeed in
reaching the cooler latitudes of the northern hemisphere, be-
cause they would be incapable of bearing the heat of the
tropics, through which they must pass. In the course of ages,
undoubtedly, exceptions would arise, and some species might
become common to the temperate and polar regions, or both
sides of the equator ; for we have before shown that the
powers of diffusion conferred on some classes are very great.
But we should confidently predict that these exceptions would
never become so numerous as to invalidate the general rule.

Some of the plants and animals transplanted by us to the
coast of Chili or Peru would never be able to cross the Andes,
so as to reach the Eastern plains ; nor, for a similar reason,
would those first established in the Pampas, or the valleys of

126

SUPPOSED CENTRES, OR FOCI, [Ch. VIII.

the Amazon and the Orinoco, ever arrive at the shores of
the Pacific.

In the ocean an analogous state of things would prevail ; for
there, also, climate would exert a great influence in limiting
the range of species, and the land would stop the migrations
of aquatic tribes as effectually as the sea arrests the dispersion
of the terrestrial. As certain birds, insects, and the seeds of
plants, can never cross the direction of prevailing winds, so
currents form natural barriers to the dissemination of many
oceanic races. A line of shoals may be as impassable to pelagian
species, as are the Alps and the Andes to plants and animals
peculiar to plains, while deep abysses may prove insuperable
obstacles to the migrations of the inhabitants of shallow waters.

It is worthy of observation, that one effect of the introduc-
tion of single pairs of each species must be the confined range
of certain groups in spots which, like small islands, or solitary
inland lakes, have few means of interchanging their inhabitants
with adjoining regions. Now this congregating, in a small
space, of many peculiar species, would give an appearance of
centres or foci of creation, as they have been termed, as if there
were favourite points where the creative energy has been in
greater action than in others, and where the numbers of peculiar
organic beings have consequently become more considerable.

We do not mean to call in question the soundness of the
inferences of some botanists, as to the former existence of cer-
tain limited spots whence species of plants have been propa-
gated, radiating, as it were, in all directions from a common
centre. On the contrary, we conceive these phenomena to be
the necessary consequences of the plan of nature before sug-
gested, operating during the successive mutations of the surface,
some of which the geologist can prove to have taken place
subsequently to the period when many species now existing
were created. In order to exemplify how this arrangement of
plants may have been produced, let us imagine that, about
three centuries before the discovery of St. Helena (itself of
submarine volcanic origin), a multitude of new isles had been

Ch, VIII.]

OF CREATION.

127

thrown up in the surrounding sea, and that these had each
become clothed with plants emigrating from St. Helena, in
the same manner as the wild plants of Campania have dif-
fused themselves over Monte Nuovo. Whenever the first
botanist investigated the new archipelago, he would, in all pro-
bability, find a different assemblage of plants in each of the
isles of recent formation; but in St. Helena itself, he would
meet with individuals of every species belonging to all parts of
the archipelago, and some, in addition, peculiar to itself, viz.,
those which had not been able to obtain a passage into any one
of the surrounding new-formed lands. In this case, it might
be truly said that the original isle was the primitive focus, or
centre, of a certain type of vegetation, whereas, in the sur-
rounding isles, there would be a smaller number of species, yet
all belonging to the same group.

But this peculiar distribution of plants would not warrant
the conclusion that, in the space occupied by St. Helena, there
had been a greater exertion of creative power than in the spaces
of equal area occupied by the new adjacent lands, because,
within the period in which St. Helena had acquired its peculiar
vegetation, each of the spots supposed to be subsequently con-
verted into land, may have been the birth-places of a great
number of marine animals and plants, which may have had
time to scatter themselves far and wide over the southern
Atlantic.

Perhaps it may be objected to some part of the foregoing
train of reasoning, that during the lapse of past ages, especially
during many partial revolutions of the globe of comparatively
modern date, different zoological and botanical provinces ought
to have become more confounded and blended together — that
the distribution of species approaches too nearly to what might
have been expected, if animals and plants had been introduced
into the globe when its physical geography had already assumed
the features which it now wears ; whereas we know that, in
certain districts, considerable geographical changes have taken

138 BROCCHI ON THE LOSS OF SPECIES. [Ch. Vltl.

place since species identical with those now in being were
created.

These, and many kindred topics, cannot be fully discussed
until we have considered, not merely the general laws which
may regulate the first introduction of species, but those which
may limit their duration on the earth. Brocchi, whose un-
timely death in Egypt is deplored by all who have the progress
of geology at heart, has remarked, when hazarding some
interesting conjectures respecting " the loss of species," that
a modern naturalist had no small assurance, who declared u that
individuals alone were capable of destruction, and that species
were so perpetuated that nature could not annihilate them, so
long as the planet lasted, or at least that nothing less than the
shock of a comet, or some similar disaster, could put an end to
their existence*." The Italian geologist, on the contrary, had
satisfied himself, that many species of testacea, which formerly
inhabited the Mediterranean, had become extinct, although a
great number of others, which had been the contemporaries of
those lost races, still survived. He came to the opinion, that
about half the species which peopled the waters when the Sub-
apennine strata were deposited, had gone out of existence ; and
in this inference he does not appear to have been far wrong.

But instead of seeking a solution of this problem, like some
other geologists of his time, in a violent and general catastrophe,
Brocchi endeavoured to imagine some regular and constant law
by which species might be made to disappear from the earth
gradually and in succession. The death, he suggested, of a
species might depend, like that of individuals, on certain pecu-
liarities of constitution conferred upon them at their birth, and
as the longevity of the one depends on a certain force of vitality,
which, after a period, grows weaker and weaker, so the duration
of the other may be governed by the quantity of prolific power
bestowed upon the species, which, after a season, may
decline in energy, so that the fecundity and multiplication of

* Necker, Phytozool. Philosophy p. 21. Brocchi, Conch. Foss. Subap., tome
L, p. 229.

Ch. VIII.]

BROCCIII ON THE LOSS OF SPECIES.

129

individuals maybe gradually lessened from century to century.
<f until that fatal term arrives, when the embryo, incapable of
extending and developing itself, abandons, almost at the instant
of its formation, the slender principle of life by which it was
scarcely animated, — and so all dies with it."

Now we might coincide in opinion with the Italian naturalist,
as to the gradual extinction of species one after another, by
the operation of regular and constant causes, without admitting
an inherent principle of deterioration in their physiological
attributes. We might concede " that many species are on the
decline, and that the day is not far distant when they will cease
to exist f 1 yet deem it consistent with what we know of the
nature of organic beings, to believe that the last individuals of
each species retain their prolific powers in their full intensity.

Brocchi has himself speculated on the share which a change
of climate may have had in rendering the Mediterranean unfit
for the habitation of certain testacea, which still continued to
thrive in the Indian ocean, and of others which were now only
represented by analogous forms within the tropics. He must
also have been aware that other extrinsic causes, such as the
progress of human population, or the increase of some one of
the inferior animals, might gradually lead to the extirpation of
a particular species, although its fecundity might remain to
the last unimpaired. If, therefore, amid the vicissitudes of the
animate and inanimate world, there are known causes capable of
bringing about the decline and extirpation of species, it be-
came him thoroughly to investigate the full extent to which
these might operate, before he speculated on any cause of so
purely hypothetical a kind, as ff the diminution of the pro-
lific virtue."

If it could have been shown that some wild plant had
insensibly dwindled away and died out, as sometimes happens
to cultivated varieties propagated by cuttings, even though
climate, soil, and every other circumstance should continue
identically the same — if any animal had perished while the
physical condition of the earth, and the number and force of
Vol. II. k

130

CAUSES WHICH DETERMINE THE

[Ch. VIII.

its foes, with every other extrinsic cause, remained unaltered,
then might we have some ground for suspecting that the
infirmities of age creep on as naturally on species as upon
individuals. But in the absence of such observations, let us
turn to another class of facts, and examine attentively the cir-
cumstances which determine the stations of particular animals
and plants,, and perhaps we shall discover, in the vicissitudes
to which these stations are exposed, a cause fully adequate to
explain the phenomena under consideration.

Stations comprehend all the circumstances, whether relating
to the animate or inanimate world, which determine whether a
given plant or animal can exist in a given locality, so that if it
be shown that stations can become essentially modified by the
influence of known causes, it will follow that species, as well as
individuals, are mortal.

Every naturalist is familiar with the fact, that although in a
particular country, such as Great Britain, there may be more
than three thousand species of plants,, ten thousand insects, and
a great variety in each of the other classes, yet there will not
be more than a hundred, perhaps not half that number, inhabit-
ing any given locality. There may be no want of space in the
supposed tract ; it may be a large mountain, or an extensive
moor, or a great river-plain, containing room enough for
individuals of every species in our island; yet the spot will
be occupied by a few to the exclusion of many, and these
few are enabled, throughout long periods, to maintain their
ground successfully against every intruder, notwithstanding
the facilities which species enjoy, by virtue of their powers of
diffusion, of invading adjacent territories.

The principal causes which enable a certain assemblage of
plants thus to maintain their ground against all others depend,
as is well known, on the relations between the physiological
nature of each species, and the climate, exposure, soil, and
other physical conditions of the locality. Some plants live
only on rocks, others in meadows, a third class in marshes.
Of the latter, some delight in a fresh-water morass,— -others in

Ch. VIII.]

STATIONS OF ANIMALS AND PLANTS.

131

salt marshes, where their roots may copiously absorb saline
particles. Some prefer an alpine region in a warm latitude,
where, during the heat of summer, they are constantly irri-
gated by the cool waters of melting snows. To others loose
sand, so fatal to the generality of species, affords the most
proper station. The Carex armaria and the Elymus arena'
rius acquire their full vigour on a sandy dune, obtaining an
ascendency over the very plants which in a stiff clay would
immediately stifle them.

Where the soil of a district is of so peculiar a nature that it
is extremely favourable to certain species, and agrees ill with
every other, the former get exclusive possession of the ground,
and, as in the case of heaths, live in societies. In like manner,
the Bog moss (Hypnum palustre) is fully developed in peaty
swamps, and becomes, like the heath, in the language of
botanists, a social plant. Such monopolies would be very fre-
quent, if the powers of a great number of species were not
equally balanced, and if animals did not interfere most actively
to preserve an equilibrium in the vegetable kingdom.

fi All the plants of a given country," says Decandolle in his
usual spirited style, " are at war one with another. The first
which establish themselves by chance in a particular spot, tend,
by the mere occupancy of space, to exclude other species — the
greater choke the smaller, the longest livers replace those
which last for a shorter period, the more prolific gradually
make themselves masters of the ground, which species multi-
plying more slowly would otherwise fill."

In this continual strife, it is not always the resources of the
plant itself which enable it to maintain or extend its ground.
Its success depends, in a great measure, on the number of its
foes or allies among the animals and plants inhabiting the same
region. Thus, for example, a herb which loves the shade may
multiply, if some tree with spreading boughs and dense foliage
flourish in the neighbourhood. Another, which, if unassisted,
would be overpowered by the rank growth of some hardy com-
petitor, is secure, because its leaves are unpalatable to cattle,

K 2

132

CAUSES WHICH DETERMINE THE

[Ch. VIII.

which, on the other hand, annually crop down its antagonist,
and rarely suffer it to ripen its seed.

Oftentimes we see some herb which has flowered in the
midst of a thorny shrub, when all the other individuals of the
same species, in the sunny fields around, are eaten down, and
cannot bring their seed to maturity. In this case, the shrub
has lent his armour of spines and prickles to protect the defence-
less herb against the mouths of the cattle, and thus a few
individuals which occupied, perhaps, the most unfavourable
station in regard to exposure, soil, and other circumstances,
may nevertheless, by the aid of an ally, become the principal
source whereby the winds are supplied with seeds which per-
petuate the species throughout the surrounding tract.

In the above example we see one plant shielding another
from the attacks of animals ; but instances are, perhaps, still
more numerous, where some animal defends a plant against the
enmity of some other subject of the vegetable kingdom.

Scarcely any beast, observes a Swedish naturalist *, will
touch the nettle, but fifty different kinds of insects are fed by
it. Some of these seize upon the root, others upon the stem ;
some eat the leaves, others devour the seeds and flowers : but
for this multitude of enemies, the nettle would annihilate a
great number of plants. Linnaeus tells us, in his Tour in
Scania, that goats were turned into an island which abounded
with the Agrostis arundinacea, where they perished by famine ;
but horses, which followed them, grew fat on the same plant.
The goat, also, he says, thrives on the meadow-sweet and water
hemlock, plants which are injurious to cattle j.

Every plant, observes Wilcke, has its proper insect allotted
to it to curb its luxuriancy, and to prevent it from multiplying
to the exclusion of others. " Thus grass in meadows sometimes
flourishes so as to exclude all other plants : here the Phalasna
graminis (Bombyx gram.'), with her numerous progeny, find a
well-spread table ; they multiply in immense numbers, and the

* Wilcke, Amoen. Acad., vol. vi., p. 17, § 12.

f Ibid., vol. vii., 409 .

Ch. VIII.]

STATIONS OF ANIMALS AND PLANTS.

133

farmer for some years laments the failure of his hay crop ; but
the grass being consumed, the moths die with hunger, or remove
to another place. Now the quantity of grass being greatly
diminished, the other plants, which were before choked by it,
spring up, and the ground becomes variegated with a multi-
tude of different species of flowers. Had not nature given a
commission to this minister for that purpose, the grass would
destroy a great number of species of vegetables, of which the
equilibrium is now kept up *."

In the above passage allusion is made to the ravages com-
mitted in 1740, and the two following years, in many provinces
of Sweden, by a most destructive insect. The same moth is
said never to touch the fox- tail grass f , so that it may be
classed as a most active ally and benefactor of that species, and
as peculiarly instrumental in preserving it in its present abun-
dance. A discovery of Rolander, cited in the treatise of
Wilcke above-mentioned, affords a good illustration of the
checks and counterchecks which nature has appointed to pre-
serve the balance of power amongst species. u The Phalsena
strobilella has the fir cone assigned to it to deposit its eggs
upon ; the young caterpillars coming out of the shell consume
the cone and superfluous seed ; but lest the destruction should
be too general, the Ichneumon strobilellae lays its eggs in the
caterpillar, inserting its long tail in the openings of the cone
till it touches the included insect, for its body is too large to
enter. Thus it fixes its minute egg upon the caterpillar, which
being hatched destroys it J."

Entomologists enumerate many parallel cases where insects,
appropriated to certain plants, are kept down by other insects,
and these again by parasites expressly appointed to prey on
them §. Few, perhaps, are in the habit of duly appreciating
the extent to which insects are active in preserving the balance

* Wilcke, Araoen. Acad., vol. vi., p. 17, § 11 and 12.
f Kirby and Spence, vol. i., p. 1 78.
t Wilcke, ibid., § 14. § Kirby and Spence, vol, iy., p. 218.

134

EQUILIBRIUM OF SPECIES

[Ch. VIII.

of species among plants, and thus regulating indirectly the
relative numbers of many of the higher orders of terrestrial
animals.

The peculiarity of their agency consists in their power of
suddenly multiplying their numbers, to a degree which could
only be accomplished in a considerable lapse of time in any of
the larger animals, and then as instantaneously relapsing, with-
out the intervention of any violent disturbing cause, into their
former insignificance.

If for the sake of employing, on different but rare occasions,
a power of many hundred horses, we were under the necessity
of feeding all these animals at great cost in the intervals when
their services were not required, we should greatly admire the
invention of a machine, such as the steam-engine, which was
capable, at any moment, of exerting the same degree of strength
without any consumption of food during periods of inaction.
The same kind of admiration is strongly excited when we con-
template the powers of insect life, in the creation of which
nature has been so prodigal. A scanty number of minute
individuals, only to be detected by careful research, are ready
in a few days, weeks, or months, to give birth to myriads
which may repress any degree of monopoly in another species,
or remove nuisances, such as dead carcasses, which might taint
the air. But no sooner has the destroying commission been
executed, than the gigantic power becomes dormant — each of
the mighty host soon reaches the term of its transient existence,
and the season arrives when the whole species passes naturally
into the egg, and thence into the larva and pupa state. In
this defenceless condition it may be destroyed either by the
elements, or by the augmentation of some of its numerous foes
which may prey upon it in these stages of its transformation ;
or it often happens that, in the following year, the season proves
unfavourable to the hatching of the eggs or the development
of the pupae.

Thus the swarming myriads depart which may have covered
the vegetation like the aphides, or darkened the air like locusts.

Ch. VIII.]

PRESERVED BY INSECTS.

135

In almost every season there are some species which in this
manner put forth their strength, and then, like Milton's spirits
which thronged the spacious hall^ " reduce to smallest forms
their shapes immense - " —

So thick the aery crowd

Swarm' d and were straiten'd ; till, the signal given,
Behold a wonder ! they but now who seem'd
In bigness to surpass earth's giant sons,
Now less than smallest dwarfs.

A few examples will illustrate the mode in which this force
operates. It is well known that among the countless species
of the insect creation, some feed on animal, others on vegetable
matter, and, upon considering a catalogue of eight thousand
British insects and arachnidae, Mr. Kirby found that these two
divisions were nearly a counterpoise to each other, the carni-
vorous being somewhat preponderant. There are also distinct
species, some appointed to consume living, others dead or putrid
animal and vegetable substances. One female, of Musca car-
naria, will give birth to twenty thousand young ; and the larva?
of many flesh-flies devour so much food in twenty-four hours,
and grow so quickly, as to increase their weight two hundred-
fold ! In five days after being hatched they arrive at their full
growth and size, so that there was ground, says Kirby, for the
assertion of Linnaeus, that three flies of M. vomitoria could de-
vour a dead horse as quickly as a lion * ; and another Swedish
naturalist remarks, that so great are the powers of propagation
of a single species, even of the smallest insects, that each can
commit, when required, more ravages than the elephant f.

Next to locusts, the aphides, perhaps, exert the greatest
power over the vegetable world, and, like them, are sometimes
so numerous as to darken the air. The multiplication of these
little creatures is without parallel, and almost every plant has
its peculiar species. Reaumur has proved, that in five gene-
rations one aphis may be the progenitor of 5,904,900,000 de-
scendants ; and it is supposed that in one year there may be

* Kirby and Spcnce,vol. i., p. 250.
f Wilcke, Amoen. Acad., chap, ii.

136

EFFECT OF INSECTS ON

[Ch. VIII.

twenty generations*. Mr. Curtis f observes, that as among
caterpillars we find some that are constantly and unalterably
attached to one or more particular species of plants, and others
that feed indiscriminately on most sorts of herbage, so it is pre-
cisely with the aphides ; some are particular, others more
general feeders; and as they resemble other insects in this
respect, so they do also in being more abundant in some years
than others. In 1793 they were the chief, and in 1798 the
sole cause of the failure of the hops. In 1794, a season almost
unparalleled for drought, the hop was perfectly free from them,
while peas and beans, especially the former, suffered very
much from their depredations.

The ravages of the caterpillars of some of our smaller moths
afford a good illustration of the temporary increase of a species.
The oak-trees of a considerable wood have been stripped of
their leaves as bare as in winter, by the caterpillars of a small
green moth (Tortrix irridana,) which has been observed the
year following not to abound t. The Gamma moth (Plusia
gamma), although one of our common species, is not dreaded
by us for its devastations, but legions of their caterpillars have,
at times, created alarm in France, as in 1735. Reaumur ob-
serves, that the female moth lays about four hundred eggs ; so
that if twenty caterpillars were distributed in a garden, and all
lived through the winter and became moths in the succeeding
May, the eggs laid by these, if all fertile, Avould produce eight
hundred thousand §. A modern writer, therefore, justly ob-
serves, that did not Providence put causes in operation to keep
them in due bounds, the caterpillars of this moth alone, leaving
out of consideration the two thousand other British species,
would soon destroy more than half of our vegetation ||.

In the latter part of the last century an ant 3 most destructive

* Kirby and Spence, vol. i., p. 174.
f Trans. Linn. Soc, vol. vi.
J Lib. Ent. Know., Insect Trans., p. 203. See Haworth Lep.
§ Reaumur, ii. 237.
|| Lib, Ent. Know., Insect Trans., p. 212.

Ch. VIII.]

THE NUMBER OF SPECIES,

137

to the sugar-cane (Formica saccharivora), appeared in such
infinite hosts, in the island of Grenada, as to put a stop to the
cultivation of that vegetable. Their numbers were incredible.
The plantations and roads were filled with them ; many domes-
tic quadrupeds, together with rats, mice, and reptiles, and even
birds, perished in consequence of this plague. It was not till
1780 that they were at length annihilated by torrents of rain,
which accompanied a dreadful hurricane *.

We may conclude by mentioning some instances of the
devastations of locusts in various countries. Among other
parts of Africa, Cyrenaica has been at different periods infested
by myriads of these creatures, which have consumed nearly
every green thing. The effect of the havoc committed by
them may be estimated by the famine they occasioned. St.
Augustin mentions a plague of this kind in Africa which
destroyed no less than eight hundred thousand men in the
kingdom of Masanissa alone, and many more upon the terri-
tories bordering upon the sea. It is also related, that in the
year 591 an infinite army of locusts migrated from Africa into
Italy, and, after grievously ravaging the country, were cast into
the sea, when there arose a pestilence from their stench which
carried off nearly a million of men and beasts.

In the Venetian territory also, in 1478, more than thirty
thousand persons are said to have perished in a famine, occa-
sioned by this scourge ; and other instances are recorded of
their devastations in France, Spain, Italy, Germany, &c. In
different parts of Russia also, Hungary, and Poland, — in Arabia
and India, and other countries, their visitations have been
periodically experienced. Although they have a preference
for certain plants, yet, when these are consumed, they will
attack almost all the remainder. In the accounts of the inva-
sions of locusts, the statements which appear most marvellous
relate to the prodigious mass of matter which encumbers the
sea wherever they are blown into it, and the pestilence arising
from its putrefaction. Their dead bodies are said to have been,

* Kirby and Spence, vol. i., p. 183. Castle, Phil. Trans., xxx., 346.

138 RECIPROCAL INFLUENCE OF [Ch. VIII.

in some places, heaped one upon another, to the depth of four
feet, in Russia, Poland, and Lithuania ; and when in southern
Africa they were driven into the sea by a north-west wind,
they formed, says Barrow, along the shore, for fifty miles, a
bank three or four feet high *. But when we consider that
forests are stripped of their foliage, and the earth of its green
garment, for thousands of square miles, it may well be supposed
that the volume of animal matter produced may equal that of
great herds of quadrupeds and flights of large birds suddenly
precipitated into the sea.

The occurrence of such events at certain intervals, in hot
countries, like the severe winters and damp summers returning
after a series of years in the temperate zone, affect the pro-
portional numbers of almost all classes of animals and plants,
and are probably fatal to the existence of many which would
otherwise thrive there, while, on the contrary, they must be
favourable to certain^pecies which, if deprived of such aid,
might not maintain their ground.

Although it may usually be remarked that the extraordinary
increase of some one species is immediately followed and
checked by the multiplication of another, yet this is not
always the case, partly because many species feed in common
on the same kinds of food, and partly because many kinds of
food are often consumed indifferently by one and the same
species. In the former case, where a variety of different ani-
mals have precisely the same taste, as, for example, when many
insectivorous birds and reptiles devour alike some particular
fly or beetle, the unusual numbers of the latter may only cause
a slight and almost imperceptible augmentation of each of those
species of bird and reptile. In the other instance, where one
animal preys on others of almost every class, as, for example,
where our English buzzards devour not only small quadru-
peds, as rabbits and field-mice, but also birds, frogs, lizards,
and insects, the profusion of any one of these last may cause
all such general feeders to subsist more exclusively upon

* Travels in Africa, p. 257. Kirpy and Spence, vol. i 7 p. 215.

Ch. VIIL]

AQUATIC AND TERRESTRIAL SPECIES.

139

the species thus in excess, and the balance may thus be
restored.

The number of species which are nearly omnivorous is con-
siderable ; and although every animal has, perhaps, a predi-
lection for some one description of food rather than another,
yet some are not even confined to one of the great kingdoms
of the organic world. Thus when the racoon of the West
Indies can neither procure fowls, fish, snails, nor insects, it will
attack the sugar-canes, and devour various kinds of grain.
The civets, when animal food is scarce, maintain themselves
on fruits and roots.

Numerous birds, which feed indiscriminately on insects and
plants, are perhaps more instrumental than any other of the
terrestrial tribes in preserving a constant equilibrium between
the relative numbers of different classes of animals and vege-
tables. If the insects become very numerous and devour the
plants, these birds will immediately derive a larger portion of
their subsistence from insects, just as the Arabians, Syrians,
and Hottentots feed on locusts, when the locusts devour their
crops.

The intimate relation of the inhabitants of the water to
those of the land, and the influence exerted by each on the
relative number of species, must not be overlooked amongst
the complicated causes which determine the existence of ani-
mals and plants in certain regions. A large proportion of the
amphibious quadrupeds and reptiles prey partly on aquatic
plants and animals, and in part on terrestrial ; and a deficiency
of one kind of prey causes them to have immediate recourse to
the other. The voracity of certain insects, as the dragon-fly, for
example, is confined to the water during one stage of their trans-
formations, and in their perfect state to the air. Innumerable
water-birds both of rivers and seas derive in like manner their
food indifferently from either element ; so that the abundance
or scarcity of prey in one induces them either to forsake or
more constantly to haunt the other. Thus an intimate con-
nexion between the state of the animate creation in a lake or

140

CAUSES OF STATIONS.

[Ch. VIII.

river, and in the adjoining dry land, is maintained ; or between
a continent, with its lakes and rivers, and the ocean. It is
well known that many birds migrate, during stormy seasons,
from the sea-shore into the interior, in search of food ; while
others, on the contrary, urged by like wants, forsake their
inland haunts, and live on substances rejected by the tide.

The migrations of fish into rivers during the spawning
season supplies another link of the same kind. Suppose the
salmon to be reduced in numbers by some marine foes, as by
seals and grampuses, the consequence must often be, that in
the course of a few years the otters at the distance of several
hundred miles inland will be lessened in number from the
scarcity of fish. On the other hand, if there be a dearth of
food for the young fry of the salmon in rivers and .estuaries,
so that few return to the sea, 'the sand-eels and other marine
species, which are usually kept down by the salmon, will
swarm in greater profusion.

It is unnecessary to accumulate a greater number of illus-
trations in order to prove that the stations of different plants
and animals depend on a great complication of circumstances, —
on an immense variety of relations in the state of the animate
and inanimate worlds. Every plant requires a certain climate,
soil, and other conditions, and often the aid of many animals,
in order to maintain its ground. Many animals feed on cer-
tain plants, being often restricted to a small number, and some-
times to one only ; other members of the animal kingdom feed
on plant-eating species, and thus become dependent on the
conditions of the stations not only of their prey, but of the
plants consumed by them.

Having duly reflected on the nature and extent of these
mutual relations in the different parts of the organic and in-
organic worlds, we may next proceed to examine the results
which may be anticipated from the fluctuations now continually
in progress in the state of the earth's surface, and in the geo-
graphical distribution of its living productions.

CHAPTER IX.

The circumstances which constitute the Stations of Animals are changeable-
Extension of the range of one species alters the condition of others — Supposed
effects which may [have followed the first entrance of the Polar Bears into
Iceland — The first appearance of a new species in a region causes the chief
disturbance — Changes known to have resulted from the advance of human
population — Whether man increases the productive powers of the earth — Indi-
genous Quadrupeds and Birds of Great Britain known to have been extirpated
— Extinction of the Dodo — Rapid propagation of the domestic Quadrupeds
over the American Continent — Power of exterminating species no prerogative of
Man — Concluding Remarks.

We have seen that the stations of animals and plants depend
not merely on the influence of external agents in the inanimate
world, and the relations of that influence to the structure and
habits of each species, but also on the state of the contem-
porary living beings which inhabit the same part of the
globe. In other words, the possibility of the existence of a
certain species in a given locality, or of its thriving more or
less therein, is determined not merely by temperature, humi-
dity, soil, elevation, and other circumstances of the like kind,
but also by the existence or non-existence, the abundance or
scarcity, of a particular assemblage of other plants and animals
in the same region.

If we show that both these classes of circumstances, whether
relating to the animate or inanimate creation, are perpetually
changing, it will follow that species are subject to incessant
vicissitudes ; and if the result of these mutations, in the course
of ages, be so great as materially to affect the general condition
of stations, it will follow that the successive destruction of
species must now be part of the regular and constant order of
Nature.

It will be desirable, first, to consider the effects which every
extension of the numbers or geographical range of one species

142

EFFECT OF THE EXTENSION

[Ch. IX.

must produce on the condition of others inhabiting the same
regions. When the necessary consequences of such extensions
have been fully explained, the reader will be prepared to
appreciate the important influence which slight modifications
in the physical geography of the globe may exert on the con-
dition of organic beings.

In the first place it is clear, that when any region is stocked
with as great a variety of animals and plants as the productive
powers of that region will enable it to support, the addition of
any new species, or the permanent numerical increase of one
previously established, must always be attended either by the
local extermination or the numerical decrease of some other
species.

There may undoubtedly be considerable fluctuations from
year to year, and the equilibrium may be again restored
without any permanent alteration ; for in particular seasons a
greater supply of heat, humidity, or other causes may augment
the total quantity of vegetable produce, in which case all the
animals subsisting on vegetable food, and others which prey
on them, may multiply without any one species giving way ;
but whenever the aggregate quantity of vegetable produce
remains unaltered, the progressive increase of one animal
or plant implies the decline of another.

All agriculturists anc] gardeners are familiar with the fact,
that when weeds intrude themselves into the space appro-
priated to cultivated species, the latter are starved in their
growth or stifled. If we abandon for a short time a field or
garden, a host of indigenous plants,

The darnel, hemlock, and rank fumitory,

pour in and obtain the mastery, extirpating the exotics, or
putting an end to the monopoly of some native plants.

If we inclose a park, and stock it with as many deer as the
herbage will support, we cannot add sheep without lessening
the number of the deer ; nor can other herbivorous species be
subsequently introduced, unless the individuals of each species
in the park become fewer in proportion.

Ch. IX.]

OF THE RANGE OF SPECIES.

143

So if there be an island where leopards are the only beasts
of prey, and the lion, tiger, and hyaana afterwards enter, the
leopards, if they stand their ground, will be reduced in num-
ber. If the locusts then arrive and swarm greatly, it may
deprive a large number of phytophagous animals of their fooc],
and thereby cause a famine, not only among them, but among
the beasts of prey ; — certain species, perhaps, which had the
weakest footing in the island will thus be annihilated.

We have seen how many distinct geographical provinces there
are of aquatic and terrestrial species, and how great are the
powers of migration conferred on different classes, whereby the
inhabitants of one region may be enabled from time to time to
invade another, and do actually so migrate and diffuse them-
selves over new countries. Now, although our knowledge of
the history of the animate creation dates from so recent a
period, that we can scarcely trace the advance or decline of
any animal or plant, except in those cases where the influence of
man has intervened, yet we can easily conceive what must
happen when some new colony of wild animals or plants
enters a region for the first time, and succeeds in establishing
itself.

Let us consider how great are the devastations committed
at certain periods by the Greenland bears, when they are
drifted to the shores of Iceland in considerable numbers on the
ice. These periodical invasions are formidable even to man ;
so that when the bears arrive, the inhabitants collect together,
and go in pursuit of them with fire-arms — each native who slays
one being rewarded by the king of Denmark. The Danes of
old, when they landed in their marauding expeditions upon
our coast, hardly excited more alarm ; nor did our islanders
muster more promptly for the defence of their lives and
property against a common enemy, than the modern Ice-
landers against these formidable brutes. It frequently hap-
pens, says Henderson, that the natives are pursued by the
bear when he has been long at sea, and when his natural
ferocity has been strengthened by the keenness of hunger ; if

144

EFFECT OF THE EXTENSION

[Ch. IX.

unarmed, it is frequently by stratagem only that they make
their escape *.

Let us cast our thoughts hack to the period when the first
polar bears reached Iceland, before it was colonized by the
Norwegians in 874 ; — we may imagine the breaking up of an
immense barrier of ice, like that which, in 1816 and the follow-
ing year, disappeared from the east coast of Greenland, which
it had surrounded for four centuries. By the aid of such
means of transportation, a great number of these quadrupeds
might effect a landing at the same time, and the havoc which
they would make among the species previously settled in the
island would be terrific. The deer, foxes, seals, and even
birds, on which these animals sometimes prey, would be soon
thinned down.

But this would be a part only, and probably an insignificant
portion, of the aggregate amount of change brought about by
the new invader. The plants on which the deer fed being
less consumed in consequence of the lessened numbers of that
herbivorous species, would soon supply more food to several
insects, and probably to some terrestrial testacea, so that the
latter would gain ground. The increase of these would fur-
nish other insects and birds with food, so that the numbers of
these last would be augmented. The diminution of the seals
would afford a respite to some fish which they had persecuted ;
and these fish, in their turn, would then multiply and press
upon their peculiar prey. Many water-fowls, the eggs and
young of which are devoured by foxes, would increase when
the foxes were thinned down by the bears ; and the fish on
which the water-fowls subsisted would then, in their turn, be
less numerous. Thus the numerical proportions of a great
number of the inhabitants, both of the land and sea, might be
permanently altered by the settling of one new species in the
region ; and the changes caused indirectly might ramify
through all classes of the living creation, and be almost end-
less.

* Journal of a Residence in Iceland, p. 276.

Ch. IX.]

OF THE RANGE OF SPECIES.

145

An actual illustration of what we have here only proposed
hypothetically, is in some degree afforded by the selection of
small islands by the eider duck for its residence during the
season of incubation ; its nests being seldom, if ever, found
on the shores of the main land, or even of a large island.
The Icelanders are so well aware of this, that they have
expended a great deal of labour in forming artificial islands,
by separating from the main-land certain promontories, joined
to it by narrow isthmuses. This insular position is neces-
sary to guard against the destruction of the eggs and young
birds, by foxes, dogs, and other animals. One year, says
Hooker* it happened that, in the small island of Vidoc,
adjoining the coast of Iceland, a fox got over upon the ice,
and caused great alarm, as an immense number of ducks were
then -sitting on their eggs or young ones. It was long before
he was taken, which was at last, however, effected by bringing
another fox to the island, and fastening it by a string near
the haunt of the former, by which he was allured within shot
of the hunter.

It is usually the first appearance of an animal or plant, in
a region to which it was previously a stranger, that gives rise
to the chief alteration ; since, after a time, an equilibrium is
again established. But it must require ages before such a new
adjustment of the relative forces of so many conflicting agents
can be definitively settled. The causes in simultaneous action
are so numerous, that they admit of an almost infinite num-
ber of combinations ; and it is necessary that all these should
have occurred once before the total amount of change, capable
of flowing from any new disturbing force, can be estimated.

Thus, for example, suppose that once in two centuries a frost
of unusual intensity, or a volcanic eruption of immense violence,
accompanied by floods from the melting of glaciers, should
occur in Iceland ; or an epidemic disease, fatal to the larger
number of individuals of some one species, and not affecting-
others, — these, and a variety of other contingencies, all of which

* Tour in Iceland, vol. i. ; p. 64, second edition.
Vol. II. L

146

CHANGES CAUSED BY THE PROGRESS

[Ch. IX.

may occur at once, or at periods separated by different inter-
vals of time, ought to happen before it would be possible for
us to declare what ultimate alteration the presence of any new
comer, such as the bear before mentioned, might occasion in
the animal population of the isle.

Every new condition in the state of the organic or inor-
ganic creation, a new animal or plant, an additional snow-clad
mountain, any permanent change, however slight in com-
parison to the whole, gives rise to a new order of things, and
may make a material change in regard to some one or more
species. Yet a swarm of locusts, or a frost of extreme in-
tensity, may pass away without any great apparent derange-
ment ; no species may be lost, and all may soon recover their
former relative numbers, because the same scourges may have
visited the region, again and again, at some former periods.
Every plant that was incapable of resisting such a degree of
cold, every animal which was exposed to be entirely cut off by
famine, in consequence of the consumption of vegetation by the
locusts, may have perished already, so that the subsequent
recurrence of similar catastrophes is attended only by a tem-
porary change.

We are best acquainted with the mutations brought about
by the progress of human population, and the growth of plants
and animals favoured by man. To these, therefore, we should,
in the first instance, turn our attention. If we conclude, from
the concurrent testimony of history and of the evidence yielded
by geological data, that man is, comparatively speaking, of
very modern origin, we must at once perceive how great a
revolution in the state of the animate world the increase of the
human race, considered merely as consumers of a certain quan-
tity of organic matter, must necessarily cause.

It may, perhaps, be said, that man has, in some degree,
compensated for the appropriation to himself of so much food,
by artificially improving the natural productiveness of soils,
by irrigation, manure, and a judicious intermixture of mineral
ingredients conveyed from different localities. But it admits

Ch. IX.]

OF HUMAN POPULATION.

147

of reasonable doubt, whether, upon the whole, we fertilize or
impoverish the lands which we occupy. This assertion may-
seem startling to many, because they are so much in the
habit of regarding the sterility or productiveness of land in
relation to the wants of man, and not as regards the organic
world generally. It is difficult, at first, to conceive, if a
morass is converted into arable land, and made to yield a crop
of grain, even of moderate abundance, that we have not im-
proved the capabilities of the habitable surface — that we have
not empowered it to support a larger quantity of organic life.
In such cases, a tract, before of no utility to man, may be
reclaimed and become of high agricultural importance, but it
may yield, at the same time, a scantier vegetation. If a lake
be drained and turned into a meadow, the space will provide
sustenance to man and many terrestrial animals serviceable to
him, but not perhaps so much food as it previously yielded to
the aquatic races.

If the pestiferous Pontine Marshes were drained and covered
with corn, like the plains of the Po, they might, perhaps,
feed a smaller number of animals than they do now ; for these
morasses are filled with of herds of buffaloes and swine, and
they swarm with birds, reptiles, and insects.

The felling of dense and lofty forests which covered, even
within the records of history, a considerable space on the
globe, now tenanted by civilized man, must usually have
lessened the amount of vegetable food throughout the space
where these woods grew. We must also take into our account
the area covered by towns, and a still larger surface occupied
by roads.

If we force the soil to bear extraordinary crops one year, we
are, perhaps, compelled to let it lie fallow the next. But
nothing so much counterbalances the fertilizing effects of human
art as the extensive cultivation of foreign herbs and shrubs,
which, although they are often more nutritious to man, seldom
thrive with the same rank luxuriance as the native plants of a
district. Man is, in truth, continually striving to diminish

L 2

148

CHANGES CAUSED BY THE PROGRESS

[Ch. IX.

the natural diversity of the stations of animals and plants in
every country, and to reduce them all to a small number fitted
for species of economical use. He may succeed perfectly in at-
taining his object, even though the vegetation be comparatively
meagre, and the total amount of animal life be greatly lessened.

Spix and Martius have given a lively description of the
incredible number of insects which lay waste the crops in
Brazil, besides swarms of monkeys, flocks of parrots and
other birds, as well as the paca, agouti, and wild swine.
They describe the torment which the planter and the natu-
ralist suffer from the musquitoes,, and the devastation of
the ants and blattse ; they speak of the dangers to which they
were exposed from the jaguar, the poisonous serpents, lizards,
scorpions, centipedes, and spiders. But with the increasing
population and cultivation of the country, observe these natu-
ralists, these evils will gradually diminish ; when the inhabi-
tants have cut down the woods, drained the marshes, made
roads in all directions, and founded villages and towns, man
will by degrees triumph over the rank vegetation and the
noxious animals, and all the elements will second and amply
recompense his activity *.

The number of human beings now peopling the earth is
supposed to amount to eight hundred millions, so that we may
easily understand how great a number of beasts of prey, birds,
and animals of every class, this prodigious population must
have displaced, independently of the still more important con-
sequences which have followed from the derangement brought
about by man in the relative numerical strength of particular
species.

Let us make some inquiries into the extent of the influence
which the progress of society has exerted, during the last seven
or eight centuries, in altering the distribution of our indigenous
British animals. Dr. Fleming has prosecuted this inquiry with
his usual zeal and ability, and in a memoir f on the subject

* Travels in Brazil, vol. i., p. 260.
f Ed. Phil. Journ., No. sxii., p. 2S7. Oct. 1824.

Ch. IX.]

OF HI' MAN POPULATION.

149

has enumerated the best-authenticated examples of the de-
crease or extirpation of certain species during a period when
our population has made the most rapid advances. We
shall offer a brief outline of his results.

The stag, as well as the fallow deer and the roe, were for-
merly so abundant that, according to Lesley, from five hundred
to a thousand were sometimes slain at a hunting-match ; but
the native races would already have been extinguished, had
they not been carefully preserved in certain forests. The otter,
the marten, and the polecat, were also in sufficient numbers to
be pursued for the sake of their fur ; but they have now been
reduced within very narrow bounds. The wild cat and fox
have also been sacrificed throughout the greater part of the
country, for the security of the poultry-yard or the fold.
Badgers have been expelled from nearly every district which
at former periods they inhabited.

Besides these, which have been driven out from some haunts,
and everywhere reduced in number, there are some which
have been wholly extirpated ; such as the ancient breed of indi-
genous horses, the wild boar, and the wild oxen, of which last,
however, a few remains are still preserved in the parks of some
of our nobility. The beaver, which was eagerly sought after
for its fur, had become scarce at the close of the ninth century,
and, by the twelfth century, was only to be met with, accord-
ing to Giraldus de Barri, in one river in Wales, and another in
Scotland. The wolf, once so much dreaded by our ancestors,
is said to have maintained its ground in Ireland so late as the
beginning of the eighteenth century (1710), though it had
been extirpated in Scotland thirty years before, and in England
at a much earlier period. The bear, which in Wales was
regarded as a beast of the chace equal to the hare or the boar*,
only perished as a native of Scotland in the year 1057 f ;

Many native birds of prey have also been the subjects of
unremitting persecution. The eagles, larger hawks, and ravens,
have disappeared from the more cultivated districts. The

* Ray, Syn. Quad,, p. 214.

f Ibid., p 295.

150

CHANGES CAUSED BY THE PROGRESS

[Ch. IX.

haunts of the mallard, the snipe, the redshank, and the bittern,
have been drained equally with the summer dwellings of the
lapwing and the curlew. But these species still linger in some
portion of the British isles ; whereas the large capercailzies,
or wood grouse, formerly natives of the pine-forests of Ire-
land and Scotland, have been destroyed within the last fifty
years. The egret and. the crane, which appear to have been
formerly very common in Scotland, are now only occasional
visitants # .

The bustard (Otis tarda), observes Graves in his British
Ornithology f , " was formerly seen in the downs and heaths of
various parts of our island, in flocks of forty or fifty birds;
whereas it is now a circumstance of rare occurrence to meet
with a single individual." Bewick also remarks, <c that they
were formerly more common in this island than at present ;
they are now found only in the open counties of the south and
east, in the plains of Wiltshire, Dorsetshire, and some parts of
Yorkshire." In the few years that have elapsed since Bewick
wrote, this bird has entirely disappeared from Wiltshire and
Dorsetshire J.

These changes, we may observe, are derived from very im-
perfect memorials, and relate only to the larger and more
conspicuous animals inhabiting a small spot on the globe ; but
they cannot fail to exalt our conception of the enormous revo-
lutions which, in the course of several thousand years, the
whole human species must have effected.

The kangaroo and the emu are retreating rapidly before the
progress of colonization in Australia ; and it scarcely admits
of doubt, that the general cultivation of that country must lead
to the extirpation of both. The most striking example of the
loss, even within the last two centuries, of a remarkable species,
is that of the dodo — a bird first seen by the Dutch when they
landed on the Isle of France, at that time uninhabited, imme-
diately after the discovery of the passage to the East Indies by

* Fleming, Syn. Quad., p. 295. f Vol. iii. London, 1821.

| Land Birds, vol. i., p. 316, Ed, 1821,

Ch. IX.]

OF HUMAN POPULATION.

151

the Cape of Good Hope, It was of a large size and singular
form ; its wings short, like those of an ostrich, and wholly
incapable of sustaining its heavy body even for a short flight.
In its general appearance it differed from the ostrich, casso-
wary, or any known bird.

Many naturalists gave figures of the dodo after the com-
mencement of the seventeenth century, and there is a painting
of it in the British Museum, which is said to have been taken
from a living individual. , Beneath the painting is a leg, in a
fine state of preservation, which ornithologists are agreed cannot
belong to any other known bird. In the museum at Oxford,
also, there is a foot and a head, in an imperfect state, but M.
Cuvier doubts the identity of this species with that of which
the' painting is preserved in London *.

In spite of the most active search, during the last century, *
no information respecting the dodo was obtained, and some
authors have gone so far as to pretend that it never existed ;
but amongst a great mass of satisfactory evidence in favour
of the recent existence of this species, we may mention that an
assemblage of fossil bones were recently discovered, under
a bed of lava, in the Isle of France, and sent to the Paris
museum by M. Desjardins. They almost all belonged to a
large living species of land-tortoise, called Testudo Indica, but
amongst them were the head, sternum, and humerus of the
dodo. M. Cuvier showed me these valuable remains in Paris,
and assured me that they left no doubt in his mind that the
huge bird was one of the gallinaceous tribe f .

* Some have complained that inscriptions on tomb-stones convey no general
information except that individuals were born and died, accidents which must
happen alike to all men. But the death of a species is so remarkable an event
in natural history, that it deserves commemoration, and it is with no small interest
that we learn, from the archives of the University of Oxford, the exact day and
year when the remains of the last specimen of the dodo, which had rotted in
the Ashmolean museum, were cast away. The relics, we are told, were " a
Musaeo subducta, annuente Vice-cancellario aliiscpie curatoribus, ad ea lastranda
convocatis, die Januarii, 8 V0 ., A.D., 1755." Zool. Journ., No. 12, p. 559. 1828.

f Sur quelcmes OssenienSj &c. Ann, des Sci., tome xxi., p. 103, Sept. 1830,

152

RAPID PROPAGATION OF

[Ch. IX.

Next to the direct agency of man, his indirect influence in
multiplying the numbers of large herbivorous quadrupeds of
domesticated races, may be regarded as one of the most obvious
causes of the extermination of species. On this, and on several
other grounds, the introduction of the horse, ox, and other
mammalia, into America, and their rapid propagation over that
continent within the last three centuries, is a fact of great
importance in natural history. The extraordinary herds of wild
cattle and horses which overran the plains of South America,
sprung from a very few pairs first carried over by the Spaniards ;
and they prove that the wide geographical range of large species
in great continents does not necessarily imply that they have
existed there from remote periods. Humboldt observes, in his
Travels *, on the authority of Azzara, that it is believed there
exist, in the Pampas of Buenos Ayres, twelve million cows and
three million horses, without comprising in this enumeration
the cattle that have no acknowledged proprietor. In the
Llanos of Caraccas, the rich hateros, or proprietors of pastoral
farms, are entirely ignorant of the number of cattle they pos-
sess. The young are branded with a mark peculiar to each
herd, and some of the most wealthy owners mark as many as
fourteen thousand a year. In the northern plains, from the
Orinoco to the lake of Maracaybo, M. Depons reckoned that
one million two hundred thousand oxen, one hundred and
eighty thousand horses, and ninety thousand mules, wandered
at large f. In some parts of the va]ley of the Mississippi,
especially in the country of the Osage Indians, "wild horses are
immensely numerous.

The establishment of black cattle in America dates from
Columbus's second voyage to St. Domingo. They there mul-
tiplied rapidly ; and that island presently became a kind of
nursery from which these animals were successively trans-
ported to various parts of the continental coast, and from
thence into the interior. Notwithstanding these numerous
exportations, in twenty-seven years after the discovery of the

* Pers. Nar., vol. iv.

f Quarterly Review, vol. xxi., p. 335.

Ch. IX.]

DOMESTIC QUADRUPEDS IN AMERICA.

153

island, herds of four thousand head, as we learn from Oviedo,
were not uncommon, and there were even some that amounted
to eight thousand. In 1587, the number of hides exported
from St. Domingo alone, according to Acosta's report, was
thirty-five thousand four hundred and forty-four ; and in the
same year there were exported sixty-four thousand three hun-
dred and fifty from the ports of New Spain. This was in the
sixty-fifth year after the taking of Mexico, previous to which
event the Spaniards, who came into that country, had not been
able to engage in anything else than war *.

All our readers are aware that these animals are now esta-
blished throughout the American continent, from Canada to
Paraguay.

The ass has thriven very generally in the New World ; and
we learn from Ulloa, that in Quito they ran wild, and multi-
plied in amazing numbers, so as to become a nuisance. They
grazed together in herds, and, when attacked, defended them-
selves with their mouths. If a horse happened to stray
into the places where they fed, they all fell upon him, and did
not cease biting and kicking till they left him dead f .

The first hogs were carried to America by Columbus, and
established in the island of St. Domingo the year following its
discovery in November, 1493. In succeeding years they were
introduced into other places where the Spaniards settled ; and,
in the space of half a century, they were found established in
the New World, from the latitude of 25° north, to the 40th
degree of south latitude. Sheep, also, and goats have mul-
tiplied enormously in the New World, as have also the cat
and the rat, which last, as we before stated, has been im-
ported unintentionally in ships. The dogs introduced by
man, which have at different periods become wild in America,
hunted in packs like the wolf and the jackal, destroying not
only hogs, but the calves and foals of the wild cattle and
horses.

* Quarterly Review, vol. xxi., p. 335.
f Ulloa's Yoyage. Wood's Zoog., vol. i., p. 9.

154 IMPORTATION OF REIN-DEER INTO ICELAND. [Ch. IX.

Ulloa in his voyage, and Buffon on the authority of old
writers, relate a fact which illustrates very clearly the principle
before explained by us, of the check which the increase of one
animal necessarily offers to that of another. The Spaniards
had introduced goats into the island of Juan Fernandez, where
they became so prolific as to furnish the pirates who infested
those seas with provisions. In order to cut off this resource
from the buccaneers, a number of dogs were turned loose into
the island ; and so numerous did they become in their turn, that
they destroyed the goats in every accessible part, after which
the number of the wild dogs again decreased *.

As an example of the rapidity with which a large tract may
become peopled by the offspring of a single pair of quadrupeds,
we may mention, that in the year 1773 thirteen rein-deer were
exported from Norway, only three of which reached Iceland.
These were turned loose into the mountains of Guldbringe
Syssel, where they multiplied so greatly, in the course of forty
years, that it was not uncommon to meet with herds consisting
of from forty to one hundred in various districts.

In Lapland, observes a modern writer, the rein-deer is a loser
by his connexion with man, but Iceland will be this creature's
paradise. There is, in the interior, a tract which Sir G. Mac-
kenzie computes at not less than forty thousand square miles,
without a single human habitation, and almost entirely unknown
to the natives themselves. There are no wolves ; the Icelanders
will keep out the bears ; and the rein-deer, being almost un-
molested by man, will have no enemy whatever, unless it has
brought with it its own tormenting gad-fly f .

Besides the quadrupeds before enumerated by us, our domes-
tic fowls have also succeeded in the West Indies and America,
where they have the common fowl, the goose, the duck, the
peacock, the pigeon, and the guinea-fowl. As these were often
taken suddenly from the temperate to very hot regions, they
were not reared at first without much difficulty ; but after a

* Buffon, vol. v., p. 100. Ulloa's Voyage, vol.;ii., p. 220.
f Travels in Iceland in 1810, p. 342,

Ch. IX.]

EFFECTS OF THE DIFFUSION OF MAN.

155

few generations they became familiarized to the climate, which,
in many cases, approached much nearer than that of Europe
to the temperature of their original native countries.

The fact of so many millions of wild and tame individuals of
our domestic species, almost all of them the largest quadrupeds
and birds, having been propagated throughout the new con-
tinent within the short period that has elapsed since the discovery
of America, while no appreciable improvement can have been
made in the productive powers of that vast continent, affords
abundant evidence of the extraordinary changes which accom-
pany the diffusion and progressive advancement of the human
race over the globe. That it should have remained for us to
witness such mighty revolutions is a proof, even if there was no
other evidence, that the entrance of man into the planet is, com-
paratively speaking, of extremely modern date, and that the
effects of his agency are only beginning to be felt.

A modern writer has estimated, that there are in America
upwards of four million square miles of useful soil, each capable
of supporting two hundred persons ; and nearly six million, each
mile capable of supporting four hundred and ninety persons *.
If this conjecture be true, it will follow, as that author observes,
that if the natural resources of America were fully developed,
it would afford sustenance to five times as great a number of
inhabitants as the entire mass of human beings existing at pre-
sent upon the globe. The new continent, he thinks, though
less than half the size of the old, contains an equal quantity of
useful soil, and much more than an equal amount of productive
power. Be this as it may, we may safely conclude that the
amount of human population now existing, constitutes but a
small proportion of that which the globe is capable of support-
ing, or which it is destined to sustain at no distant period, by
the rapid progress of society, especially in America, Australia,
and certain parts of the old continent.

But if we reflect that already many millions of square miles
of the most fertile land, occupied originally by a boundless

* l^aclaren. Art. America, Encyc. Britannica.

156 POWER OF EXTERMINATING SPECIES [Ch. IX.

variety of animal and vegetable forms, have been already
brought under the dominion of man, and compelled, in a great
measure, to yield nourishment to him, and to a limited number
of plants and animals which he has caused to increase, we must
at once be convinced, that the annihilation of a multitude of
species has already been effected, and will continue to go on
hereafter, in certain regions, in a still more rapid ratio, as the
colonies of highly-civilized nations spread themselves over un-
occupied lands.

Yet, if we wield the sword of extermination as we advance,
we have no reason to repine at the havoc committed, nor to
fancy, with the Scotch poet, that " we violate the social union
of nature or complain, with the melancholy Jaques, that we

Are mere usurpers, tyrants, and, what's worse,
To fright the animals, and to kill them up
In their assign'd and native dwelling-place.

We have only to reflect, that in thus obtaining possession
of the earth by conquest, and defending our acquisitions by
force, we exercise no exclusive prerogative. Every species
which has spread itself from a small point over a wide area,
must, in like manner, have marked its progress by the diminu-
tion, or the entire extirpation, of some other, and must main-
tain its ground by a successful struggle against the encroach-
ments of other plants and animals. That minute parasitic
plant, called " the rust " in wheat, has, like the Hessian fly,
the locust, and the aphis, caused famines ere now amongst the
" lords of the creation." The most insignificant and diminu-
tive species, whether in the animal or vegetable kingdom, have
each slaughtered their thousands, as they disseminated them-
selves over the globe, as well as the lion, when first it spread
itself over the tropical regions of Africa.

We cannot conclude this division of our subject without ob-
serving, that although we have as yet considered one class only
of the causes (the organic) whereby species may become exter-
minated, yet the continued action of these alone, throughout
myriads of future ages ? must work an entire change in the

Ch. IX.]

NO PREROGATIVE OF MAN.

157

state of the organic creation, not merely on the continents and
islands, where the power of man is chiefly exerted, but in the
great ocean, where his control is almost unknown. The mind
is prepared by the contemplation of such future revolutions
to look for the signs of others, of an analogous nature, in the
monuments of the past. Instead of being astonished at the
proofs there manifested of endless mutations in the animate
world, they will appear to one who has thought profoundly on
the fluctuations now in progress, to afford evidence in favour of
the uniformity of the system, unless, indeed, we are precluded
from speaking of uniformity when we characterize a principle
of endless variation.

CHAPTER X.

Influence of inorganic causes in changing the ^habitations of speecis — Powers
of difFusion indispensable, that each species may maintain its ground — How
changes in the physical geography affect the distribution of species — Rate of
the change of species cannot be uniform, however regular the action of the
inorganic causes — Illustration derived from subsidences by earthquakes — from
the elevation of land by the same — from the formation of new islands — from
the wearing through of an isthmus — Each change in the physical geography
of large regions must occasion the extinction of species — Effects of a general
alteration of climate on the migration of species — Gradual refrigeration causes
species in the northern and southern hemispheres to become distinct — Elevation
of temperature the reverse — Effects in the distribution of species which must
result from vicissitudes in climate inconsistent with the theory of transmutation.

Having shown in the last chapter how considerably the
numerical increase or the extension of the geographical range
of any one species must derange the numbers and distribution
of others, let us now direct our attention to the influence which
the inorganic causes described in our first volume are con-
tinually exerting on the habitations of species.

So great is the instability of the earth's surface, that if
Nature were not continually engaged in the task of sowing
seeds and colonizing animals, the depopulation of a certain
portion of the habitable sea and land would in a few years be
considerable. Whenever a river transports sediment into a
lake or sea, the aquatic animals and plants which delight in
deep water are expelled : the tract, however, is not allowed to
remain useless, but is soon peopled by species which require
more light and heat, and thrive where the water is shallow.
Every addition made to the land by the encroachment of the
delta of a river banishes many subaqueous species from their
native abodes; but the new-formed plain is not permitted to
lie unoccupied, being instantly covered with terrestrial vege-
tation. The ocean devours continuous lines of sea-coast, and

Ch. X.]

POWERS OF MIGRATION INDISPENSABLE.

159

precipitates forests or rich pasture-land into the waves ; but
this space is not lost to the animate creation, for shells and sea-
weed soon adhere to the new-made cliffs, and numerous fish
people the channel which the current has scooped out for itself.
No sooner has a volcanic isle been thrown up than some lichens
begin to grow upon it, and it is sometimes clothed with verdure,
while smoke and ashes are still occasionally thrown from the
crater. The cocoa, pandanus, and mangrove take root upon
the coral reef before it has fairly risen above the waves. The
burning stream of lava that descends from Etna rolls through
the stately forest, and converts to ashes every tree and herb
which stand in its way ; but the black strip of land thus deso-
lated, is covered again, in the course of time, with oaks, pines,
and chestnuts, as luxuriant as those which the fiery torrent
swept away.

Every flood and landslip, every wave which a hurricane
or earthquake throws upon the shore, every shower of volcanic
dust and ashes which buries a country far and wide to the
depth of many feet, every advance of the sand-flood, every
conversion of salt-water into fresh when rivers alter their
main channel of discharge, every permanent variation in the
rise or fall of tides in an estuary — these and countless other
causes displace in the course of a few centuries certain plants
and animals from stations which they previously occupied. If,
therefore, the Author of Nature had not been prodigal of those
numerous contrivances before alluded to, for spreading all
classes of organic beings over the earth — if he had not ordained
that the fluctuations of the animate and inanimate creation
should be in perfect harmony with each other, it is evident that
considerable spaces, now the most habitable on the globe, would
soon be as devoid of life as are the Alpine snows, or the dark
abysses of the ocean, or the moving sands of the Sahara.

The powers then of migration and diffusion conferred on
animals and plants, are indispensable to enable them to main-
tain their ground, and would be necessary even though it were
never intended that a species should gradually extend its geo-

160 EFFECT OF CHANGES IN PHYSICAL GEOGRAPHY [Ch. X.

graphical range. But a facility of shifting their quarters
being once given, it cannot fail to happen that the inhabitants
of one province should occasionally penetrate into some other,
since the strongest of those barriers which we before described
as separating distinct regions, are all liable to be thrown down
one after the other, during the vicissitudes of the earth's
surface.

The numbers and distribution of particular species are
affected in two ways, by changes in the physical geography of
the earth. First, these changes promote or retard the migra-
tions of species ; secondly, they alter the physical conditions
of the localities which species inhabit. If the ocean should
gradually wear its way through an isthmus, like that of Suez,
it would open a passage for the intermixture of the aquatic
tribes of two seas previously disjoined, and would, at the same
time, close a free communication which the terrestrial plants
and animals of two continents had before enjoyed. These
would be, perhaps, the most important consequences in regard
to the distribution of species, which would result from the
breach made by the sea in such a spot ; but there would be
others of a distinct nature, such as the conversion of a certain
tract of land which formed the isthmus into sea. This space
previously occupied by terrestrial plants and animals would be
immediately delivered over to the aquatic, a local revolution
which might have happened in innumerable other parts of the
globe, without being attended by any alteration in the blending
together of species of two distinct provinces.

This observation leads us to point out one of the most
interesting conclusions to which we are led by the contempla-
tion of the vicissitudes of the inanimate world in relation to
those of the animate. It is clear that if the agency of in-
organic causes be uniform as we have supposed, they must ope-
rate very irregularly on the state of organic beings, so that the
rate according to which these will change in particular regions
will not be equal in equal periods of time.

We are not about to advocate the doctrine of general catas-

Ch. X.]

ON THE DISTRIBUTION OF SPECIES.

161

trophes recurring at certain intervals, as in the ancient oriental
cosmogonies, nor do we doubt that if very considerable periods
of equal duration could be taken into our consideration and
compared one with another, the rate of change in the living,
as well as in the inorganic world, would be nearly uniform ;
but if we regard each of the causes separately, which we know
to be at present the most instrumental in remodelling the state
of the surface, we shall find that we must expect each to be in
action for thousands of years, without producing any extensive
alterations in the habitable surface, and then to give rise,
during a very brief period, to important revolutions.

We shall illustrate this principle by a few of the most
remarkable examples which present themselves. In the course
of the last century, as we have before pointed out, a considerable
number of instances are recorded of the solid surface, whether
covered by water or not, having been permanently sunk or
upraised by the power of earthquakes. Most of these con-
vulsions are only accompanied by temporary fluctuations in
the state of limited districts, and a continued repetition of
these events for thousands of years might not produce any
decisive change in the state of many of those great zoological or
botanical provinces of which we have sketched the boundaries.

When, for example, large parts of the ocean and even of in-
land seas are a thousand fathoms or upwards in depth it is a
matter of no moment to the animate creation that vast tracts
should be heaved up many fathoms at certain intervals, or
should subside to the same amount. Neither can any material
revolution be pi-oduced in South America either in the terres-
trial or the marine plants or animals by a series of shocks on
the coast of Chili, each of which, like that of Penco, in 1750,
should uplift the coast about twenty-five feet. Nor if the
ground sinks fifty feet at a time, as in the harbour of Port
Royal, in Jamaica, in 1692, will such alterations of level work
any general fluctuations in the state of organic beings inhabit-
ing the West India islands, or the Caribbean Sea.

It is only when these subterranean powers, by shifting
Vol. II. ftj

16£ EFFECT OF CHANGES IN PHYSICAL GEOGRAPHY [Ch. X.

gradually the points where their principal force is developed,
happen to strike upon some particular region where a slight
change of level immediately affects the distribution of land
and water, or the state of the climate, or the barriers between
distinct groups of species over extensive areas, that the rate of
fluctuation becomes accelerated, and may, in the course of a
few years or centuries, work mightier changes than had been
experienced in myriads of antecedent years.

Thus, for example, a repetition of subsidences causing the
narrow isthmus of Panama to sink down a few hundred feet,
might in a few centuries bring about a great revolution in
the state of the animate creation in the western hemisphere.
Thousands of aquatic species would pass for the first time
from the Caribbean Sea into the Pacific ; and thousands of
others, before peculiar to the Pacific ocean, would make their
way into the Caribbean Sea, the Gulf of Mexico, and the
Atlantic. A considerable modification would probably be oc-
casioned by the same event in the direction or volume of the
Gulf-stream, and thereby the temperature of the sea and the
contiguous lands would be altered as far as the influence of
that current extends. A change of climate might thus be
produced in the ocean from Florida to Spitzbergen, and in
many countries of North America, Europe, and Greenland.
Not merely the heat, but the quantity of rain which falls would
be altered in certain districts, so that many species would be
excluded from tracts where they before flourished ; others
would be reduced in number ; and some would thrive more
and multiply. The seeds also and the fruits of plants would no
longer be drifted in precisely the same directions, nor the eggs
of aquatic animals ; neither would species be any longer im-
peded in their migrations towards particular stations before
shut out from them by their inability to cross the mighty
current.

Let us take another example from a part of the globe which
is at present liable to suffer by earthquakes, viz., the low
sandy tract which intervenes between the sea of Azof and the

Ch. X.] ON THE DISTRIBUTION OF SPECIES. 16S

Caspian. If there should occur a sinking down to a trifling
amount, and such ravines should be formed as might be pro-*
duced by a few earthquakes., not more considerable than have
fallen within our limited observation during the last one hun-
dred and forty years, the waters of the sea of Azof would pour
rapidly into the Caspian, which, according to the lowest esti-
mate, is fifty feet lower than the level of the Black Sea, and
which, according to some writers of considerable authority, is
one hundred and fifty feet, — according to others, three hun-
dred feet below the level of the Sea of Azof*. The latter
sea would immediately borrow from the Euxine, the Euxine
from the Mediterranean, and the Mediterranean from the
Atlantic, so that an inexhaustible current would pour down
into the low tracts of Asia bordering the Caspian, by which
all the sandy salt steppes adjacent to that sea would be in*
undated.

The diluvial waters would reach the salt lake of Aral, nor
stop until their eastern shores were bounded by the high land
which in the steppe of the Kirghis connects the Altay with
the Himalaya mountains. A few years, perhaps a few months
might suffice for the accomplishment of this great revolution
in the geography of the interior of Asia ; and it is impossible
for those who believe in the permanence of the energy with
which existing causes now act, not to anticipate such events
again and again in the course of future ages.

Let us next imagine a few cases of the elevation of land of
small extent at certain critical points, as, for example, in the
shallowest parts of the Straits of Gibraltar, where the sound-*
ings from the African to the European side give only two
hundred and twenty fathoms. In proportion as this sub-
marine barrier of rock was upheaved, to effect which would
merely require the shocks of partial and confined earthquakes,
the volume of water which pours in from the Atlantic into the
Mediterranean would be lessened. But the loss of the inland
sea by evaporation would remain the same, so that being no

* Malte-Brun, vol. vi. p. 405.

M 2

164 EFFECT OF CHANGES IN PHYSICAL GEOGRAPHY [Ch. X.

longer able to draw on the ocean for a supply sufficient to
restore its equilibrium, it must sink, and leave dry a certain
portion of land around its borders. The current which now
flows constantly out of the Black Sea into the Mediterranean
would then rush in more rapidly, and the level of the Mediter-
ranean would be thereby prevented from falling so low ; but
the level of the Black Sea would, for the same reason, sink, so
that when, by a continued series of elevatory movements, the
Straits of Gibraltar had become completely closed up, we
might expect large and level sandy steppes to surround both
the Euxine and Mediterranean, like those occurring at present
on the skirts of the Caspian, and the sea of Aral. The geo-
graphical range of hundreds of aquatic species would be
thereby circumscribed, and that of hundreds of terrestrial
plants and animals extended.

A line of submarine volcanos crossing the channel of some
strait, and gradually choking it up with ashes and lava, might
produce a new barrier as effectually as a series of earth-
quakes ; especially if thermal springs, plentifully charged with
carbonate of lime, silica, and other mineral ingredients, should
promote the rapid multiplication of corals and shells, and
cement them together with solid matter precipitated during
the intervals between eruptions. Suppose in this manner a
stoppage to be caused of the Bahama Channel between the
bank of that name and the coast of Florida. This insignificant
revolution, confined to a mere spot in the bottom of the ocean,
would, by diverting the main current of the Gulf-stream, give
rise more effectually than the opening of the Straits of Panama
before supposed, to extensive changes in the climate and
distribution of animals and plants inhabiting the northern
hemisphere.

A repetition of elevatory movements of earthquakes might
continue over an area as extensive as Europe, for thousands
of ages, at the bottom of the ocean in certain regions, and
produce no visible effects ; whereas, if they should operate in
some shallow parts of the Pacific, amid the coral archipelagos,

Ch. X.]

ON THE DISTRIBUTION OF SPECIES.

165

they would soon give birth to a new continent. Hundreds
of volcanic islands may be thrown up and become covered
with vegetation, without causing more than local fluctuations
in the animate world ; but if a chain like the Aleutian archipe-
lago or the Kurile isles, run for a distance of many hundred
miles, so as to form an almost uninterrupted communication
between two continents, or two distant islands, the migrations
of plants, birds, insects, and even of some quadrupeds, may
cause in a short time an extraordinary series of revolutions,
tending to augment the range of some animals and plants, and
to limit that of others. A new archipelago might be formed
in the Mediterranean, the Bay of Biscay, and a thousand
other localities, and might produce less important events than
one rock which should rise up between Australia and Java*
so placed that winds and currents might cause an interchange
of the plants, insects, and birds, of the latter countries.

If we turn from the igneous to the aqueous agents, we find
the same tendency to an irregular rate of change, naturally
connected with the strictest uniformity in the energy of those
causes. When the sea, for example, gradually encroaches
upon both sides of a narrow isthmus, as that of Sleswick,
separating the North Sea from the Baltic, where, as we stated,
the cliffs on both the opposite coasts are wasting away % no
material alteration results for thousands of years, save only that
there is a progressive conversion of a small strip of land into
water. A few feet only, or a few yards, are annually removed ;
but when at last the partition shall be broken down, and the
tides of the ocean shall enter by a direct passage into the in-
land sea, instead of going by a circuitous route through the
Cattegat, a body of salt-water will sweep up as far as the
Gulfs of Bothnia and Finland, the waters of which are now
brackish, or almost fresh ; and this revolution will be attended
by the local annihilation of many species.

Similar consequences must have resulted, on a small scale,
when the sea opened its way through the isthmus of Staveren

* Vol. i. p. 289.

166 EFFECT OF CHANGES IN PHYSICAL GEOGRAPHY [Ch.X.

in the thirteenth century, forming an union between an inland
lake and the ocean, and opening, in the course of one century,
a shallow strait more than half as wide as the narrowest part
of that which divides England from France.

It will almost seem superfluous, after we have thus traced
the important modifications in the condition of living beings
which flow from changes of trifling extent, to argue that entire
revolutions might be brought about, if the climate and physical
geography of the whole globe were greatly altered. Species we
have stated are, in general, local, some being confined to ex-
tremely small spots, and depending for their existence on a com-
bination of causes which, if they are to be met with elsewhere,
occur only in some very remote region. Hence it must happen
that when the nature of these localities is changed the species
will perish ; for it will rarely happen that the cause which
alters the character of the district will afford new facilities to
the species to establish itself elsewhere.

If we attribute the origin of a great part of the desert of
Africa to the gradual progress of moving sands, driven east-
ward by the westerly winds, we may safely infer that a variety
of species must have been annihilated by this cause alone. The
sand-flood has been inundating, from time immemorial, the
rich lands on the west of the Nile, and we have only to mul-
tiply this effect a sufficient number of times, in order to under-
stand how, in the lapse of ages, a whole group of terrestrial
animals and plants may become extinct.

This desert, without including Bornou and Darfour, extends,
according to the calculation of Humboldt, over one hundred
and ninety-four thousand square leagues, an area far more than
double that of the Mediterranean, which occupies only seventy-
nine thousand eight hundred square leagues. In a small por-
tion of so vast a space, we may infer, from analogy, that there
were many peculiar species of plants and animals which must
ljave been banished by the sand, and their habitations invaded
by the camel and by birds and insects formed for the arid
sands.

Ch.X.3 ON THE DISTRIBUTION OF SPECIES. 167

There is evidently nothing in the nature of the catastrophe
to favour the escape of the former inhabitants to some adjoin-
ing province ; nothing to weaken, in the bordering lands, that
powerful barrier against emigration — pre-occupancy. Nor,
even if the exclusion of a certain group of species from a given
tract were compensated by an extension of their range over a
new country, would that circumstance tend to the conservation
of species in general ; for the extirpation would merely then be
transferred to the region so invaded. If it be imagined, for
example, that the aboriginal quadrupeds, birds, and other ani-
mals of Africa emigrated in consequence of the advance of
drift-sand, and colonized Arabia, the indigenous Arabian
species must have given way before them, and have been
reduced in number or destroyed.

Let us next suppose that, in some central and. more elevated,
parts of the great African desert, the upheaving power of
earthquakes should be exerted throughout an immense series
of ages, accompanied, at certain intervals, by volcanic erup-
tions such as gave rise at once, in 1755, to a mountain one
thousand seven hundred feet high, on the Mexican plateau.
When the continued repetition of these events had caused a
mountain-chain, it is obvious that a complete transformation
in the state of the climate would be brought about throughout
a vast area.

We will imagine the summits of the new chain to rise so as
to be covered, like Mount Atlas, for several thousand feet,
with snow during a great part of the year. The melting of
these snows, during the greatest heat, would cause the rivers
to swell in the season when the greatest drought now prevails ;
the waters, moreover, derived from this source, would always
be of lower temperature than the surrounding atmosphere, and
would thus contribute to cool the climate. During the nu-
merous earthquakes and volcanic eruptions which would attend
the gradual formation of the chain, there would be many floods,
caused by the bursting of temporary lakes and by the melting
of snows by lava. These inundations would deposit alluvial

168 EFFECT OF CHANGES IN PHYSICAL GEOGRAPHY [Ch. X.

matter far and wide over the original sands at all levels, as the
country assumed various shapes, and was modified again and
again by the moving power from below, and the aqueous
erosion of the surface above. At length the Sahara would be
fertilized, irrigated by rivers and streamlets intersecting it in
every direction, and covered by jungle and morasses, so that
the animals and plants which now people northern Africa
would disappear, and the region would gradually become fitted
for the reception of a population of species perfectly dissimilar
in their forms, habits, and organization.

There are always some peculiar and characteristic features
in the physical geography of each large division of the globe ;
and on these peculiarities the state of animal and vegetable life
is dependent. If, therefore, we admit incessant fluctuations in
the physical geography, we must, at the same time, concede
the successive extinction of terrestrial and aquatic species to be
part of the economy of our system. When some great class of
stations is in excess in certain latitudes, as, for example, in
wide savannahs, arid sands, lofty mountains, or inland seas, we
find a corresponding development of species adapted for such
circumstances. In North America, where there is a chain
of vast inland lakes of fresh-water, we find an extraordinary
abundance and variety of aquatic birds, fresh-water fish, tes-
tacea, and small amphibious reptiles, fitted for such a climate.
The greater part of these would perish if the lakes were de-
stroyed, — an event that might be brought about by some of
the least of those important revolutions contemplated in geo-
logy. It might happen that no fresh-water lakes of corre-
sponding magnitude might then exist on the globe ; but if they
occurred elsewhere, they might be situated in New Holland,
Southern Africa, Eastern Asia, or some region so distant as to
be quite inaccessible to the North American species ; or they
might be situated within the tropics, in a climate uninhabitable
by species fitted for a temperate zone ; or, finally, we may
presume that they would be pre-occupied by indigenous tribes.

To pursue this train of reasoning farther is unnecessary; the

Oh. X.]

ON THE DISTRIBUTION OF SPECIES.

169

reader has only to reflect on what we have said of the habita-
tions and the stations of organic beings in general, and to
consider them in relation to those effects which we have con-
templated in our first volume as resulting from the igneous
and aqueous causes now in action, and he will immediately
perceive that, amidst the vicissitudes of the earth's surface,
species cannot be immortal, but must perish one after the other,
like the individuals which compose them. There is no pos-
sibility of escaping from this conclusion, without resorting to
some hypothesis as violent as that of Lamarck, who imagined,
as we have before seen, that species are each of them endowed
with indefinite powers of modifying their organization, in con-
formity to the endless changes of circumstances to which they
are exposed.

Some of the effects which must attend every general altera-
tion of climate are sufficiently peculiar to claim a separate
consideration before concluding the present chapter. _

We have before stated that, during seasons of extraordinary
severity, many northern birds, and, in some countries, many
quadrupeds, migrate southwards. If these cold seasons were
to become frequent, in consequence of a gradual and general
refrigeration of the atmosphere, such migrations would be more
and more regular, until, at length, many animals, now con-
fined to the arctic regions, would become the tenants of the
temperate zone ; while the inhabitants of the latter would
approach nearer to the equator. At the same time, many
species previously established on high mountains, would begin
to descend, in every latitude, towards the middle regions, and
those which were confined to the flanks of mountains would
make their way into the plains. Analogous changes would
also take place in the vegetable kingdom.

If, on the contrary, the heat of the atmosphere be on the
increase, the plants and animals of low grounds would ascend
to higher levels, the equatorial species would migrate into the
temperate zone, and those of the temperate into the arctic circle.

But although some species might thus be preserved, every

I7d EFFECTS OF CHANGES OF CLIMATE [Ch. X.

great change of climate must be fatal to many which can find
no place of retreat, when their original habitations become
unfit for them. For if the general temperature be on the
rise, then is there no cooler region whither the polar species
can take refuge ; if it be on the decline, then the animals and
plants previously established between the tropics have no
resource. Suppose the general heat of the atmosphere to in-
crease, so that even the arctic region became too warm for the
musk-ox and rein-deer, it is clear that they must perish ; so,
if the torrid zone should lose so much of its heat by the pro-
gressive refrigeration of the earth's surface, as to be an unfit
habitation for apes, boas, bamboos, and palms, these tribes of
animals and plants, or at least most of the species now belong-
ing to them, would become extinct, for there would be no
warmer latitudes for their reception.

It will follow, therefore, that as often as the climates of the
globe are passing from the extreme of heat to that of cold — -
from the summer to the winter of the great year before alluded
to by us* — the migratory movement will be directed constantly
from the poles towards the equator ; and for this reason the
species inhabiting parallel latitudes, in the northern and
southern hemispheres, must become widely different. For
we assume, on grounds before stated f, that the original stock
of each species is introduced into one spot of the earth only,
and, consequently, no species can be at once indigenous in the
arctic and antarctic circles.

But when, on the contrary, a series of changes in the phy-
sical geography of the globe, or any other supposed cause,
occasions an elevation of the general temperature, — when there
is a passage from the winter to one of the vernal or summer
seasons of the great cycle of climates, then the order of the
migratory movement is inverted. The different species of
animals and plants direct their course from the equator towards
the poles ; and the northern and southern hemispheres may
become peopled, to a great degree, by identical species. Such
* Vol.i.,p. 116. f Chap. VIII.

•Ch. X,]

ON THE DISTRIBUTION OF SPECIES*

171

is not the actual state of the inhabited earth, as we have already
shown in our sketch of the geographical distribution of its
living productions ; and this fact adds one more additional
proof to a great body of evidence, derived from independent
sources, that the general temperature has been cooling down
during the epochs which immediately preceded our own.

We do not mean to speculate on the entire transposition of
a group of animals and plants from tropical to polar latitudes,
or the reverse, as a probable, or even possible, event; for
although we believe the mean annual temperature of one zone
to be transferrible to another, we know that the same climate
cannot be so transferred. Whatever be the general tempera-
ture of the earth's surface, comparative equability of heat will
characterize the tropical regions, while great periodical variations
will belong to the temperate, and still more to the polar lati-
tudes. These, and many other peculiarities connected with
heat and light, depend on fixed astronomical causes, such as
the motion of the earth and its position in relation to the sun,
and not on those fluctuations of its surface, which may influ-
ence the general temperature.

Among many obstacles to such extensive transferences of
habitations, we must not forget the immense lapse of time re-
quired, according to any hypothesis yet suggested, especially
that which has appeared to us most feasible, to bring about a
considerable change in climate. During a period so vast, the
other causes of extirpation, before enumerated by us, would
exert so powerful an influence as to prevent all, save a very few
hardy species, from passing from equatorial to polar regions,
or from the tropics to the pole.

But the power of accommodation to new circumstances is
great in certain species, and might enable many to pass from
one zone to another, if the mean annual heat of the atmosphere
and the ocean were greatly altered. To the marine tribes,
especially, such a passage would be possible, for they are less
impeded in their migrations, by barriers of land, than are the
terrestrial by the ocean. Add to this, that the temperature of

172 EFFECTS OF CHANGES OF CLIMATE [Ch. X.

the ocean is much more uniform than that of the atmosphere in-
vesting the land, so that we may easily suppose that most of the
testacea, fish, and other classes, might pass from the equatorial
into the temperate regions, if the mean temperature of those
regions were transposed, although a second expatriation of
these species of tropical origin into the arctic and antarctic
circles would probably be impossible.

On the principles above explained, if we found that at some
former period, as when, for example, our carboniferous strata
were deposited, the same tree-ferns and other plants inhabited
the regions now occupied by Europe and Van Dieman's Land,
we should suspect that the species in question had, at some
antecedent period, inhabited lands within the tropics, and that
an increase of the mean annual heat had caused them to emi-
grate into both the temperate zones. There are no geological
data, however, as yet obtained, to warrant the opinion that
such identity of species existed in the two hemispheres in the
era in question.

Let us now consider more particularly the effect of vicissi-
tudes of climate in causing one species to give way before the
increasing numbers of some other.

When temperature forms the barrier which arrests the pro-
gress of an animal or plant in a particular direction, the
individuals are fewer and less vigorous as they approach the
extreme confines of the geographical range of the species.
But these stragglers are ready to multiply rapidly on the
slightest increase or diminution of heat that may be favourable
to them, just as particular insects increase during a hot sum-
mer, and certain plants and animals gain ground after a series
of congenial seasons.

In almost every district, especially if it be mountainous, there
are a variety of species the limits of whose habitations are con-
terminous, some being unable to proceed farther without
encountering too much heat, others, too much cold. Individuals,
which are thus on the borders of the regions proper to their
respective species, are like the out-posts of hostile armies,

Ch. X.]

ON THE DISTRIBUTION OF SPECIES.

173

ready to profit by every slight change of circumstances in their
favour, and to advance upon the ground occupied by their
neighbours and opponents.

The proximity of distinct climates, produced by the inequal-
ities of the earth's surface, brings species possessing very dif-
ferent constitutions into such immediate contact, that their
naturalizations are very speedy whenever opportunities of
advancing present themselves. Many insects and plants, for
example, are common to low plains within the arctic circle,
and to lofty mountains in Scotland and other parts of Europe.
If the climate, therefore, of the polar regions were transferred
to our own latitudes, the species in question would immediately
descend from these elevated stations to overrun the low
grounds. Invasions of this kind, attended by the expulsion
of the pre-occupants, are almost instantaneous, because the
change of temperature not only places the one species in a more
favourable position, but renders the others sickly and almost
incapable of defence.

Lamarck appears to have speculated on the modifications to
which every variation of external circumstances might give rise
in the form and organization of species, as if he had indefinite
periods of time at his command, not sufficiently reflecting that
revolutions in the state of the habitable earth, whether by
changes of climate or any other condition, are attended by still
greater fluctuations in the relative condition of contemporary
species. They can avail themselves of these alterations in their
favour instantly, and augment their numbers to the injury of
some other species ; whereas the supposed transmutations are
only assumed to be brought about by slow and insensible de-
grees, and in a lapse of ages, the duration of which is beyond
the reach of human conception Even if we thought it possible
that the palm or the elephant, which now flourish in equatorial
regions, could ever learn to bear the variable seasons of our
temperate zone, or the rigours of an arctic winter, we should,
with no less confidence, affirm, that they must perish before
they had time to become habituated to such new circumstances.

174

EFFECTS OF CHANGES OF CLIMATE

[Ch. X.

That they would be supplanted by other species at each varia-
tion of climate, may be inferred from what we have before said
of the known local exterminations of species which have resulted
from the multiplication of others. Some minute insect, per-
haps, might be the cause of destruction to the huge and
powerful elephant.

Suppose the climate of the highest part of the woody zone
of Etna to be transferred to the sea-shore at the base of the
mountain, no botanist would anticipate that the olive, lemon-
tree, and prickly pear (Cactus opuntia), would be able to con-
tend with the oak and chestnut, which would begin forthwith
to descend to a lower level, or that these last would be able to
stand their ground against the pine, which would also, in the
space of a few years, begin to occupy a lower position. We
might form some kind of estimate of the time which might be
required for the migrations of these plants ; whereas we have
no data for concluding that any number of thousands of years
would be sufficient for one step in the pretended metamor-
phosis of one species into another, possessing distinct attributes
and qualities.

This argument is applicable not merely to climate, but to
any other cause of mutation. However slowly a lake may be
converted into a marsh, or a marsh into a meadow, it is evident
that before the lacustrine plants can acquire the power of living
in marshes, or the marsh-plants of living in a less humid soil,
other species, already existing in the region, and fitted for
these several stations, will intrude and keep possession of the
ground. So if a tract of salt-water becomes fresh by passing
through every intermediate degree of brackishness, still the
marine molluscs will never be permitted to be gradually meta-
morphosed into fluviatile species ; because long before any such
transformation can take place by slow and insensible degrees,
other tribes, which delight in brackish or fresh-water, will avail
themselves of the change in the fluid, and will, each in their
turn, monopolize the space.

It is idle to dispute about the abstract possibility of the con-

Ch. X.]

ON THE DISTRIBUTION OF SPECIES.

175

version of one species into another, when there are known causes
so much more active in their nature, which must always inter-
vene and prevent the actual accomplishment of such conversions.
A faint image of the certain doom of a species less fitted to
struggle with some new condition in a region which it pre-
viously inhabited, and where it has to contend with a more
vigorous species, is presented by the extirpation of savage tribes
of men by the advancing colony of some civilized nation. In
this case the contest is merely between two different races, each
gifted with equal capacities of improvement — between two
varieties, moreover, of a species which exceeds all others in its
aptitude to accommodate its habits to the most extraordinary
variations of circumstances. Yet few future events are more
certain than the speedy extermination of the Indians of North
America and the savages of New Holland in the course of a
few centuries, when these tribes will be remembered only in
poetry and tradition.

CHAPTER XI.

Theory of the successive extinction of species consistent with their limited geo-
graphical distribution — The discordance in the opinions of botanists respecting
the centres from which plants have been diffused may arise from changes in
physical geography subsequent to the origin of living species — Whether there
are grounds for inferring that the loss from time to time of certain animals and
plants is compensated by the introduction of new species ? — Whether any
evidence of such new creations could be expected within the historical era, even
if they had been as frequent as cases of extinction ? — The question whether
the existing species have been created in succession can only be decided by
reference to geological monuments.

We have pointed out in the preceding chapters the strict
dependence of each species of animal and plant on certain
physical conditions in the state of the earth's surface, and on
the number and attributes of other organic beings inhabiting
the same region. We have also endeavoured to show that all
these conditions are in a state of continual fluctuation, the
igneous and aqueous agents remodelling, from time to time,
the physical geography of the globe, and the migrations of
species causing new relations to spring up successively between
different organic beings. We have deduced as a corollary,
that the species existing at any particular period must, in the
course of ages, become extinct one after the other. " They
must die out," to borrow an emphatical expression from Buffon,
" because Time fights against them."

If the views which we have taken are just, there will be no
difficulty in explaining why the habitations of so many species
are now restrained within exceedingly narrow limits. Every
local revolution, such as those contemplated in the preceding
chapter, tends to circumscribe the range of some species, while
it enlarges that of others ; and as we have been led to infer
that new species originate in one spot only, each must require
time to diffuse itself over a wide area, The recent origin,

Ch. XI.]

CENTRES OF VEGETATION.

177

therefore, of some species, and the high antiquity of others, may-
be equally consistent with the general fact of their limited dis-
tribution, some being local, because they have not existed long
enough to admit of their wide dissemination ; others, because
circumstances in the animate or inanimate world have occurred
to restrict the range which they may once have obtained.

As considerable modifications in the relative levels of land
and sea have taken place, in certain regions, since the existing
species were in being, we can feel no surprise that the zoologist
and botanist have hitherto found it difficult to refer the geo-
graphical distribution of species to any clear and determinate
pi-inciples, since they have usually speculated on the pheno-
mena, upon the assumption that the physical geography of tbe
globe had undergone no material alteration since the introduc-
tion of the species now living. So long as this assumption was
made, the facts relating to the geography of plants and animals
appeared capricious in the extreme, and by many the subject
was pronounced to be so full of mystery and anomalies, that
the establishment of a satisfactory theory was hopeless.

Some botanists conceived, in accordance with the hypothesis
of Willdenow, that mountains were the centres of creation from
which the plants now inhabiting large continents have radiated,
to which Decandolle and others, with much reason, objected,
that mountains, on the contrary, are often the barriers between
two provinces of distinct vegetation. The geologist who is
acquainted with the extensive modifications which the surface
of the earth has undergone in very recent geological epochs,
may be able, perhaps, to reconcile both these theories in their
application to different regions.

A lofty range of mountains, which is so ancient as to
date from a period when the species of animals and plants
differed from those now living, will naturally form a barrier
between contiguous provinces ; but a chain which has been
raised, in great part, within the epoch of existing species, and
around which new lands have arisen from the sea within that
period, will be a centre of peculiar vegetation.

Vol. II. N

178

CENTRES OF VEGETATION.

[Gh. XI.

t( In France," observes Decandolle*, " the Alps and Ce-
vennes prevent a great number of the plants of the south from
spreading themselves to the northward ; but it has been re-
marked that some species have made their way through the
gorges of these chains, and are found on their northern sides,
principally in those places where they are lower and more
interrupted." Now the chains here alluded to have probably
been of considerable height, even since the era when the exist-
ing vegetation began to appear, and were it not for the deep
fissures which divide them, they might have caused much more
abrupt terminations to the extension of distinct assemblages of
species.

Parts of the Italian peninsula, on the other hand, have
gained a considerable portion of their present height since a
majority of the marine species now inhabiting the Mediterra-
nean, and probably, also, since the terrestrial plants of the same
region, were in being. Large tracts of land have been added,
both on the Adriatic and Mediterranean side, to what origi-
nally constituted a much narrower range of mountains, if not
a chain of islands running nearly north and south, like Cor-
sica and Sardinia. It may, therefore, be presumed, that the
Apennines have been a centre whence species have diffused
themselves over the contiguous lower and newer regions. In
this and all analogous situations, the doctrine of Willdenow,
that species have radiated from the mountains as from centres,
may be well founded.

It appears from Mr. Brown's remarks on the vegetation of
New Holland, that there are two groups of plants occurring
between the thirty-third and thirty-fifth degrees of southern
latitude, and principally at the two opposite extremities of this
tract, that is, near the eastern and western coasts. These points
have been termed the two principal foci of Australian vegeta-
tion, each of them possessing certain genera which are almost
peculiar to it f. If, when this continent has been more tho-

* Essai Elementaire, &c, p. 46.
f Brown's Appendix to FUnders's Voyage, and Prichard, Phys. Hist, of Man-
kind, vol.i., p. 31.

Ch.XL]

APPEARANCE OF NEW SPECIES.

179

roughly investigated, we do not discover some physical barriers,
such as a great marsh, or a desert, or a lofty mountain-chain,
now intervening between these districts, there may, perhaps,
be geological evidence hereafter discovered, that a sea was
interposed up to a modern period separating two large
islands. Sufficient time may not have elapsed since the union
of such isles, to allow of a complete intermixture by mutual
immigrations.

If the reader should infer, from the facts laid before him in
the preceding chapters, that the successive extinction of animals
and plants may be part of the constant and regular course of
nature, he will naturally inquire whether there are any means
provided for the repair of these losses? Is it part of the
economy of our system that the habitable globe should, to a
certain extent, become depopulated both in the ocean and on
the land ; or that the variety of species should diminish until
some new era arrives when a new and extraordinary effort of
creative energy is displayed ? Or is it possible that new species
can be called into being from time to time, and yet that so
astonishing a phenomenon can escape the observation of natu-
ralists ?

Humboldt has characterized these subjects as among the
mysteries which natural science cannot reach ; and he ob-
serves, that the investigation of the origin of beings does not
belong to zoological or botanical geography. To geology,
however, these topics do strictly appertain ; and this science is
only interested in inquiries into the state of the animate crea-
tion as it now exists, with a view of pointing out its relations
to antecedent periods when its condition was different.

. Before offering any hypothesis towards the solution of so
difficult a problem, let us consider what kind of evidence we
ought to expect, in the present state of science, of the first
• appearance of new animals or plants, if we could imagine the
successive creation of species to constitute, like their gradual
extinction, a regular part of the economy of nature.

In the first place it is obviously more easy to prove that a

N 2

180

SPECULATIONS ON THE

[Ch. XI.

species, once numerously represented in a given district, has
ceased to be, than that some other which did not pre-exist has
made its appearance — assuming always, for reasons before
stated, that single stocks only of each animal and plant are
originally created, and that individuals of new species do not
suddenly start up in many different places at once.

So imperfect has the science of Natural History remained
down to our own times, that within the memory of persons
now living, the numbers of known animals and plants have
been doubled, or even quadrupled, in many classes. New and
often conspicuous species are annually discovered in parts of
the old continent, long inhabited by the most civilized nations.
Conscious, therefore, of the limited extent of our information,
we always infer, when such discoveries are made, that the
beings in question had previously eluded our research ; or had
at least existed elsewhere, and only migrated at a recent period
into the territories where we now find them. It is difficult
even in contemplation to anticipate the time when we shall be
entitled to make any other hypothesis in regard to all the
marine tribes, and to by far the greater number of the terres-
trial — such as birds, which possess such unlimited powers of
migration ; insects which, besides their numbers, are also so
capable of being diffused to vast distances ; and cryptogamous
plants, to which, as to many other classes, both of the animal
and vegetable kingdom, similar observations are applicable.

What kind of proofs, therefore, could we reasonably expect
to find of the origin at a particular period of a new species ?

Perhaps it may be said in reply, that within the last two or
three centuries some forest tree or new quadruped might have
been observed to appear suddenly in those parts of England
or France which had been most thoroughly investigated ;
— that naturalists might have been able to shew that no such
being inhabited any other region of the globe, and that there
was no tradition of anything similar having before been ob-
served in the district where it had made its appearance.

Now although this objection may seem plausible, yet its

Ch. XL]

APPEARANCE OF NEW SPECIES.

181

force will be found to depend entirely on the rate of fluctua-
tion which we suppose to prevail in the animate world, and on
the proportion which such conspicuous subjects of the animal
and vegetable kingdoms bear to those which are less known,
and escape our observation. There are probably more than a
million, perhaps two millions of species of plants and animals,
exclusive of the microscopic and infusory animalcules, now in-
habiting the terraqueous globe. The terrestrial plants, it is
supposed, may amount, if fully known, to about one hundred
thousand, and the insects to four times that number. To these
we have still to add for the remainder of the terrestrial classes,
many of the invertebrated and all the vertebrated animals. As
to the aquatic tribes, it remains at present in a great degree
mere matter of conjecture what proportion they bear to the
denizens of the land ; but the habitable surface beneath the
waters can hardly be estimated at less than double that of the
continents and islands, even admitting that a very consider-
able area is destitute of life, in consequence of great depth,
cold, darkness, and other circumstances. In the late polar
expedition it was found that in some regions, as in Baffin's
Bay, there were marine animals inhabiting the bottom at great
depths, where the temperature of the water was below the
freezing point. That there is life at much greater profundities
in warmer regions may be confidently inferred. We have be-
fore stated that marine plants not only exist but acquire vivid
colours at depths where, to our senses, there would be dark-
ness deep as night.

The ocean teems with life — the class of polyps alone are
conjectured by Lamarck to be as strong in individuals as
insects. Every tropical reef is described as bristling with
corals, budding with sponges, and swarming with crustacea,
echini, and testacea; while almost every tide- washed rock is
carpeted with fuci and studded with corallines, actinias, and
mollusca. There are innumerable forms in the seas of the
warmer zones, which have scarcely begun to attract the atten-
tion of the naturalist ; and there are parasitic animals without

182

SPECULATIONS ON THE

[Ch. XI.

number, three or four of which are sometimes appropriated to
one genus, as to the BalcBna, for example. Even though
we concede, therefore, that the geographical range of marine
species is more extensive in general than that of the terrestrial,
(the temperature of the sea being more uniform, and the land
impeding less the migrations of the oceanic than the ocean
those of the terrestrial,) yet we think it most probable that
the aquatic species far exceed in number the inhabitants of
the land.

Without insisting on this point, we may safely assume, as
we before stated, that, exclusive of microscopic beings, there
are between one and two millions of species now inhabiting the
terraqueous globe ; so that if only one of these were to become
extinct annually, and one new one were to be every year called
into being, moi'e than a million of years would be required to
bring about a complete revolution in organic life.

We are not hazarding at present any hypothesis as to the
probable rate of change, but none will deny that when we pro-
pose as a mere speculation the annual birth and the annual
death of one species on the globe, we imagine no slight degree
of instability in the animate creation. If we divide the surface
of the earth into twenty regions of equal area, one of these
might comprehend a space of land and water about equal in
dimensions to Europe, and might contain a twentieth part of
the million of species which we will suppose to exist. In this
region one species only would, according to the rate of mor-
tality before assumed, perish in twenty years, or only five out
of fifty thousand in the course of a century. But as a con-
siderable pi'oportion of the whole would belong to the aquatic
classes, with which we have a very imperfect acquaintance, we
may exclude them from our consideration, and thus one only
might be lost in about forty years among the terrestrial tribes.
Now the mammiferous quadrupeds in Great Britain are only
to other terrestrial species of organic beings, both plants and
animals, in the proportion of about one to two hundred and
eighty ; and taking this as a rude approximation to a general

Ch. XI.]

APPEARANCE OF NEW SPECIES.

183

standard, it would require more than eight thousand years
before it would come to the turn of this conspicuous class to
lose one of their number even in a region of the dimensions
of Europe.

It is easy, therefore, to conceive, that in a small portion of
such an area, in countries, for example, of the size of England
and France, periods of much greater duration must elapse
before it would be possible to authenticate the first appearance
of one of the larger plants and animals, assuming the annual
birth and death of one species to be the rate of vicissitude in
the animate creation throughout the world.

The observations of naturalists may, in the course of future
centuries, accumulate positive data, from which an insight into
the laws which govern this part of our terrestrial system may
be derived ; but, in the present deficiency of historical records,
we have traced up the subject to that point where geological
monuments alone are capable of leading us on to the discovery
of ulterior truths. To these, therefore, we must now appeal,
carefully examining the strata of recent formation wherein the
remains of living species, both animal and vegetable, are known
to occur. We must study these strata in strict reference to
their chronological order as deduced from their superposition,
and other relations. From these sources we may learn which
of the species, now our contemporaries, have survived the
greatest revolutions of the earth's surface ; which of them have
co-existed with the greatest number of animals and plants now
extinct, and which have made their appearance only when the
animate world had nearly attained its present condition.

From such data we may be enabled to infer whether species
have been called into existence in succession or all at one
period ; whether singly, or whether by groups simultaneously ;
whether the antiquity of man be as high as that of any of the
inferior beings which now share the planet with him, or
whether the human species is one of the most recent of the
whole.

184

APPEARANCE OF NEW SPECIES.

[Ch. XI.

To some of these questions we can even now return a satis-
factory answer; and with regard to the rest, we have some
data to guide conjecture, and to enable us to speculate with
advantage : but it would be premature to anticipate such dis-
cussions until we have laid before the reader an ample body
of materials amassed by the industry of modern geologists.

CHAPTER XII.

Effects produced by the powers of vitality on the state of the earth's surface —
Modifications in physical geography caused by organic beings on dry land in-
ferior to those caused in the subaqueous regions — Why the vegetable soil does
not augment in thickness — Organic matter drifted annually to the sea, and buried
in subaqueous strata — Loss of nourishment from this source, how supplied —
The theory, that vegetation is an antagonist power counterbalancing the degra-
dation caused by running water, untenable — That the igneous causes are the
true antagonist powers, and not the action of animal and vegetable life — Con-
servative influence of vegetation — Its bearing on the theory of the formation of
valleys, and on the age of the cones of certain extinct volcanos — Rain dimi-
nished by the felling of forests — Distribution of the American forests dependent
on the direction of the predominant winds — Influence of man in modifying the
physical geography of the globe.

The second branch of our inquiry, respecting the changes of
the organic world, relates to the effects produced by the powers
of vitality on the state of the earth's surface, and on the mate-
rial constituents of its crust.

By the effects produced on the surface, we mean those modi-
fications in physical geography of which the existence of
organic beings is the direct cause, — as when the growth of cer-
tain plants covers the slope of a mountain with peat, or con-
verts a swamp into dry land ; or when vegetation prevents the
soil, in certain localities, from being washed away by running
water.

By the agency of the powers of vitality on the material con-
stituents of the earth's crust, we mean those permanent modi-
fications in the composition and structure of new strata, which
result from the imbedding therein of animal and vegetable
remains. In this case, organic beings may not give rise imme-
diately to any new features in the physical geography of
certain tracts, which would not equally have resulted from the
mere operation of inorganic causes ; as, for example, if a lake
be filling up with sediment, held in suspension by the waters

186 EFFECTS OF THE POWERS OF VITALITY [Ch. XII.

of some river, and with mineral matter precipitated from the
waters of springs, the character of the deposits may be modified
by aquatic animals and plants, which may convert the earthy
particles into shell,, peat, and other substances : but the lake
may, nevertheless, be filled up in the same time, and the new
strata may be deposited in nearly the same order as would have
prevailed if its waters had never been peopled by living beings.

In treating of the first division of our subject we may remark,
that when we talk of alterations in physical geography, we are
apt to think too exclusively of that part of the earth's surface
which has emerged from beneath the waters, and with which
alone, as terrestrial beings, we are familiar. Here the direct
power of animals and plants to cause any important variations
is, of necessity, very limited, except in checking the progress
of that decay of which the land is the chief theatre. But if we
extend our views, and instead of contemplating the dry land
we consider that larger portion which is assigned to the aquatic
tribes, we discover the immediate influence of the living crea-
tion, in imparting varieties of conformation to the solid exterior
which the sole agency of inanimate causes would not produce,
to be very great.

Thus, when timber is floated into the sea, it is often drifted
to vast distances and subsides in spots where there might have
been no deposit, at that time and place, if the earth had not
been tenanted by living beings. If, therefore, in the course
of ages, a hill of wood, or lignite, be thus formed in the sub-
aqueous regions, a change in the submarine geography may
be said to have resulted from the action of organic powers.
So in regard to the growth of coral reefs : it is probable that
almost all the matter of which they are composed is supplied
by mineral springs, which we know often rise up at the bottom
of the sea, and which, on land, abound throughout volcanic
regions thousands of miles in extent. The matter thus con-
stantly given out could not go on accumulating for ever in the
waters, but would be precipitated in the abysses of the sea, even
if there were no polyps and testacea ; but these animals arrest

Ch. XII.]

ON THE STATE OF THE EARTIl's SURFACE.

and secrete the carbonate of lime on the summits of submarine
mountains, and form reefs many hundred feet in thickness, and
hundreds of leagues in length, where, but for them, none might
ever have existed.

If no such voluminous masses are formed on the land, it is
not from the want of solid matter in the structure of terres-
trial animals and plants, but merely because, as we have so
often stated, the continents are those parts of the globe where
accessions of matter can scarcely ever take place, — where, on
the contrary, the most solid parts already formed are, each in
their turn, exposed to gradual degradation. The quantity of
timber and vegetable matter which grows in a tropical forest
in the course of a century is enormous, and multitudes of
animal skeletons are scattered there in the same period, besides
innumerable land-shells and other organic substances. The
aggregate of these materials might constitute, perhaps, a mass
greater in volume than that which is produced in any coral-
reef during the same lapse of years ; but, although this process
should continue on the land for ever, no mountains of wood or
bone would be seen stretching far and wide over the country,
or pushing out bold promontories into the sea.

The whole solid mass is either devoured by animals, or
decomposes, as does a portion of the rock and soil on which
the animals and plants are supported. For the decompo-
sition of the strata themselves, especially of their alkaline
ingredients and of the organic remains which they so fre-
quently include, is one source from whence running water and
the atmosphere may derive the materials which are absorbed
by the roots and leaves of plants. Another source is the passage
into a gaseous form of even the hardest parts of animals and
plants which die and are exposed to putrefy in the air, where
they are soon resolved into the elements of which they are com-
posed ; and while a portion of these parts is volatilized, the
rest is taken up by rain-water and sinks into the earth or flows
towards the sea, so that they enter again and again into the
composition of different organic beings.

188

WHY VEGETABLE MATTER DOES NOT

[Ch. XII.

The principal elements found in plants are hydrogen, carbon,
and oxygen, so that water and the atmosphere contain all of
them, either in their own composition or in solution *. The
constant supply of these elements is maintained not only by
the putrefaction of animal and vegetable substances, and the
decay of rocks before mentioned, but also by the copious evo-
lution of carbonic acid and other gases from volcanos and
mineral springs, and by the effects of ordinary evaporation,
whereby aqueous vapours are made to rise from the ocean and
to circulate round the globe.

It is well known that when two gases of different specific
gravity are brought into contact, even though the heavier be
the lowermost, they become uniformly diffused by mutual
absorption through the whole space which they occupy. By
virtue of this law, the heavy carbonic acid finds its way up-
wards through the lighter air, and conveys nourishment to the
lichen which covers the mountain top.

The fact, therefore, that the vegetable mould which covers
the earth's surface does not decrease in thickness, will not
altogether bear out the argument which was founded upon it
by Playfair. This vegetable soil, he observes, consists partly
of loose earthy materials easily removed, in the form of sand
and gravel, partly of finer particles suspended in the waters,
which tinge those of some rivers continually, and those of all
occasionally, when they are flooded. The soil, although con-
tinually diminished from this cause, " remains the same in
quantity, or at least nearly the same, and must have done so
ever since the earth was the receptacle of animal or vegetable
life. The soil, therefore, is augmented from other causes,
just as much, at an average, as it is diminished by that now
mentioned ; and this augmentation evidently can proceed from
nothing but the constant and slow disintegration of the
rocks f ."

* See some good remarks on the Formation of Soils, BakewelPs Geology,
chap, xviii.

f Illust. of Hutt. Theory, § 103.

Ch.XIL] INCREASE ON THE SURFACE OF THE LAND.

189

That the repair of the earthy portion of the soil can only
proceed, as PJayfair suggests, from the decomposition of rocks,
may be admitted ; but the vegetable matter may be supplied,
and is actually furnished in a great degree, by absorption from
the atmosphere, as we before mentioned, so that in level situa-
tions, such as in platforms that intervene between valleys where
the action of running water is very trifling, the fine vegetable
particles carried off by the rain may be perpetually restored,
not by the waste of the rock below, but from the air above.

If we supposed the quantity of food consumed by terrestrial
animals, together with the matter absorbed by them in breath-
ing, and the elements imbibed by the roots and leaves of plants,
to be derived entirely from that supply of hydrogen, carbon,
oxygen, azote, and other elements, given out into the atmos-
phere and the waters by the putrescence of organic substances,
then we might imagine that the vegetable mould would, after
a series of years, neither gain nor lose a single particle by the
action of organic beings. This conclusion is not far from the
truth ; but the operation which renovates the vegetable and
animal mould is by no means so simple as that here supposed.
Thousands of carcasses of terrestrial animals are floated down
every century into the sea, and, together with forests of drift-
timber, are imbedded in subaqueous deposits, where their
elements are imprisoned in solid strata, and may there remain
throughout whole geological epochs before they again become
subservient to the purposes of life.

On the other hand, fresh supplies are derived by the atmos-
phere, and by running water, as we before stated, from the
disintegration of rocks and their organic contents, and from
the interior of the earth, from whence all the elements before-
mentioned, which enter principally into the composition of
animals and vegetables, are continually evolved. Even nitrogen
has been recently found to be contained very generally in the
waters of mineral springs *.

* Dr. Daubeny has ascertained this interesting fact in his late tour on the con-
tinent.

190

VEGETATION NO COUNTERPOISE

[Ch. XII.

If we suppose that the copious discharge from the nether
regions, by springs and volcanic vents, of carbonic acid and
other gases, together with the decomposition of rocks, may be
just sufficient to counterbalance that loss of matter which,
having already served for the nourishment of animals and
plants, is annually carried down in organized forms, and
buried in subaqueous strata, we believe that we concede the
utmost that is consistent with probability. When more is
required by a theorist — when we are told that a counterpoise
is. derived from the same source to that enormous disintegra-
tion of solid rock and its transportation to lower levels, which
is the annual result of the action of rivers and marine currents,
we must entirely withhold our assent. Such an opinion has
been recently advanced by an eminent geologist, or we should
have deemed it unnecessary to dwell on propositions which
appear to us so clear and obvious.

The descriptions which we gave of the degradation yearly
going on through the eastern shores of England, and of the
enormous weight of solid matter hourly rolled down by the
Ganges or the Mississippi, have been represented as extreme
cases, calculated to give a partial view of the changes now in
progress, especially as we omitted, it is said, to point out the
silent but universal action of a great antagonist power, whereby
the destructive operations before alluded to are neutralized,
and even, in a great degree, counterbalanced.

i( Are there," says Professor Sedgwick, " no antagonist
powers in nature to oppose these mighty ravages — no conser-
vative principle to meet this vast destructive agency ? The
forces of degradation very often of themselves produce their
own limitation. The mountain-torrent may tear up the solid
rock and bear its fragments to the plain below; but there its
power is at an end, and the rolled fragments are left behind to
a new action of material elements. And what is true of a
single rock, is true of a mountain -chain ; and vast regions on
the surface of the earth, now only the monuments of spoliation
and waste, may hereafter rest secure under the defence of a

Ch. XII.]

TO THE LEVELLING POWER OF WATER.

191

thick vegetable covering, and become a new scene of life and
animation.

<c It well deserves remark that the destructive powers of
nature act only upon lines, while some of the grand principles
of conservation act upon the whole surface of the land. By
the processes of vegetable life an incalculable mass of solid
matter is absorbed, year after year, from the elastic and non-
elastic fluids circulating round the earth, and is then thrown
down upon its surface. In this single operation there is a
vast counterpoise to all the agents of destruction. And the
deltas of the Ganges and the Mississippi are not solely formed
at the expense of the solid materials of our globe, but in part,
and I believe also in a considerable part, by one of the great
conservative operations by which the elements are made to
return into themselves

This is splendid eloquence, full of the energy and spirit
that breathes through the whole address : —

Monte decurrens velut amnis, imbres
Quem super uotas aluere ripas,
Fervet, immensusque ruit —

but we must pause for a moment, lest we be hurried away by
its tide. Let us endeavour calmly to consider whither it would
carry us.

If by the elements returning into themselves be meant their
return to higher levels, it is certainly possible that a fraction
of the organic matter which is intermixed with the mud and
sand deposited in alternate strata in the delta of the Ganges,
may have been derived by the leaves and roots of plants from
such aqueous vapour, carbonic acid, and other gases, as had
ascended into the atmosphere from lower regions, and which
were not, therefore, derived from the waste of rocks and their
organic contents, or from the putrescence of vegetables pre-
viously nourished from these sources. This fraction, and this
alone, may then be deducted from the mass of solid matter
annually transported into the Bay of Bengal, and what re-
Address to the Geological Society on the Anniversary, Feb, 1831, p. 24.

VEGETATION NO COUNTERPOISE

[Ch. XII.

mains, whether organic or inorganic, will be the measure of
the degradation which thousands of torrents in the Himalaya
mountains, and many rivers of other parts of India, bring
down in a single year. Even in this case it will be found
that the sum of the force of vegetation can merely be con-
sidered as having been in a slight degree conservative, retard-
ing the waste of land, and not acting as an antagonist power.

But the untenable nature of the doctrine which we are now
controverting may be set in a clearer light by examining the
present state of the earth's surface, on which it is declared that
f< an incalculable mass of solid matter is thrown down year
after year," in such a manner as to form a counterpoise to
the agents of decay. Is it not a fact that the vegetable mould
is seldom more than a few feet in thickness, and that it often
does not exceed a few inches ? Do we find that its volume
is more considerable on those parts of our continents which we
can prove, by geological data, to have been elevated at more
ancient periods, and where there has been the greatest time
for the accumulation of vegetable matter, produced through-
out successive zoological epochs? On the contrary, are not
these higher and older regions more frequently denuded, so as
to expose the bare rock to the action of the sun and air ?

Do we find in the torrid zone, where the growth of plants is
most rank and luxurious, that accessions of matter due to their
agency are most conspicuous on the surface of the land ? On
the contrary, is it not there where the vegetation is most active
that, for reasons to be explained in the next chapter, even
those superficial peat mosses are unknown which cover a large
area in some parts of our temperate zone ? If the operation
of animal and vegetable life could restore to the general sur-
face of the continents a portion of the elements of those dis-
integrated rocks, of which such enormous masses are swept
down annually into the sea, along particular river-courses and
lines of coast, the effects would have become ere now most
striking ; and would have constituted one of the most leading
features in the structure and composition of our continents.

Ch.XIL]

TO THE LEVELLING POWER OF WATER*

193

All the great steppes and table-lands of the world, where the
action of running water is feeble, would have become the
grand repositories of organic matter, accumulated without that
intermixture of sediment which so generally characterizes the
subaqueous strata.

Even the formation of peat in certain districts where the
climate is cold and moist, the only case, perhaps, which
affords the shadow of a support to the theory under considera-
tion, has not in every instance a conservative tendency. A
peat-moss often acts like a vast sponge, absorbing water in.
large quantities, and swelling to the height of many yards
above the surrounding country. The turfy covering of the
bog serves, like the skin of a bladder, to retain for a while the
fluid within, and a violent inundation sometimes ensues when
that skin bursts, as has often happened in Ireland, and many
parts of the continent. Examples will be mentioned by us in
a subsequent chapter, where the Stygian torrent has hollowed
out ravines and borne along rocks and sand, in countries where
such ravages could not have happened but for the existence of
peat. Here, therefore, the force of vegetation accelerates the
rate of decay of land, and the solid matter swept down to
lower levels during such floods, counterbalances, to a certain
degree, the accessions of vegetable mould which may accrue to
the land by the growth of peat.

We may explain more clearly the kind of force which we
imagine vegetation to exert, by comparing it to the action
of frost, which augments the height of some few Alpine sum-
mits by causing a mass of perpetual snow to lodge thereon, or
fills up some valleys with glaciers ; but although by this pro-
cess of congelation the rain-water that has risen by evaporation
from the sea, is retained for awhile in a solid form upon the
land, and although some elevated spots may be protected from
waste by a constant covering of ice, yet by the sudden melting
of snow and ice, the degradation of rocks is often accelerated*
Although every year fresh snow and ice are formed, as also
more vegetable and animal matter, yet there is no increase;
Vol. II. O

194 IGNEOUS CAUSES THE ANTAGONIST POWER [CJj. XII.

the one melts, the other putrifies, or is drifted down to the
sea by rivers. If this were not the case, frost might be con-
sidered as an antagonist power, as well as the action of animal
and vegetable life, and these by their combined energy might
restore to continents a portion of that solid matter which is
swept down into the sea from mountains and wasting cliffs.
By the aid of such machinery might a theorist repair the
losses of the solid land, sand and rocky fragments being
carried down annually to the subaqueous regions from hills
of granite, limestone, and shale, while vegetation and frost
might raise new mountains, which, like the cliffs in Esch-
scholtz's Bay, might consist of icebergs, intermixed with
vegetable mould.

We have stated in a former volume that, in the known
operation of the igneous causes, a real antagonist power is
found which may counterbalance the levelling action of run-
ning water; and there seems no good reason for presuming
that the upheaving and depressing force of earthquakes, to-
gether with the heaping up of ejected matter by volcanos,
may not be fully adequate to restore the superficial inequali-
ties which rivers and oceanic currents annually tend to lessen.
If a counterpoise be derived from this source, the quantity
and elevation of land above the sea may for ever remain the
same, in spite of the action of the aqueous causes, which, if
thus counteracted, may never be able to reduce the surface
of the earth more nearly to a state of equilibrium than that
which it has now attained ; and, on the other hand, the force
of the aqueous agents themselves might thus continue for
ever unimpaired. This permanence of the intensity of the
powers now in operation would account for any amount of
disturbance or degradation of the earth's crust, so far as the
mere quantity of movement or decay is concerned ; provided
only that indefinite periods of time are contemplated.

As to the intensity of the disturbing causes at particular
epochs, their effects have as yet been studied for too short a
time to enable us fully to compare the signs of ancient con-

Ch.XII.]

TO THE ACTION OF RUNNING WATER.

195

vulsions with the permanent monuments left in the earth's
crust by the events of the last few thousand years. But not-
withstanding the small number of changes which have been
witnessed and carefully recorded, observation has at least
shown that our knowledge of the extent of the subterranean
agency , as now developed from time to time, is in its infancy;
and there can be no doubt that great partial mutations in the
structure of the earth's crust are brought about in volcanic
regions, without any interruption to the general tranquillity
of the habitable surface.

Some geologists point to particular cases of enormous dis-
location of ancient date, and confessedly not of frequent
occurrence, where shifts in the strata of two thousand feet and
upwards appear to have been produced suddenly and at one
effort. But they have been at no pains to prove that similar
consequences could not result from earthquakes such as have
happened within the last three thousand years. They have
usually proceeded on a priori reasoning to assume that such
convulsions were paroxysmal, and attended by catastrophes
such as have never occurred in modern times. It would be
irrelevant to the subject immediately under consideration to
enter into a long digression on these topics, but we may re-
mind the reader, that the subsidence of the quay at Lisbon to
the depth of six hundred feet only gave rise to a slight whirl-
pool ; and we may thence infer the possibility of a sinking down
or elevation four or five times as great, especially in deeper seas,
without any superficial disturbance unparalleled in the events
of the last century.

If a certain sect of geologists were as anxious to reconcile
the actual and former course of nature as they are eager to
contrast them, they would perceive that the effects witnessed
by us of subterranean action on supramarine land, may not be
a type of those which the submerged rocks undergo, and
they would proceed with more caution when reasoning from
a comparison between the accumulated results of disturb-
ing causes in the immensity of past time, and those which

O 2

196

SYNCHRONISM OF THE ACTION

[Ch. xir.

are recorded in the meagre annals of a brief portion of the
human era.

The same rash generalizations which are now made respect-
ing eras of paroxysmal violence and chaotic derangement, led
formerly to the doctrines of universal formations, the improba-
bility of which might have been foreseen by a slight reference
to the causes now in operation.

To the same modes of philosophising we may ascribe the
unwillingness of some naturalists to admit, that all the fossil
species are not the same as those now living on the globe;
whereas, if the facts and reasoning set forth in a former part
of this volume, respecting the present instability of the organic
creation be just, it might always a priori have been seen that
the species inhabiting the planet at two periods very remote
could hardly be identical.

In our view of the Huttonian theory, we pointed out as one
of its principal defects, the assumed want of synchronism in
the action of the great antagonist powers — the introduction,
first, of periods when continents gradually wasted away, and
then of others when new lands were elevated by violent con-
vulsions. In order to have a clear conception of the working
of such a system, let the reader suppose the earthquakes and
volcanic eruptions of the Andes to be suspended for a million
of years, and sedimentary deposits to accumulate throughout
the whole of that period, as they now accumulate at the
mouths of the Orinoco and Amazon, and along the inter-
vening coast. Then let a period arrive when the subter-
ranean power, which had obtained no vent during those ten
thousand centuries, should escape suddenly in one tremendous
explosion.

It is natural that geologists who reject such portions of the
Huttonian theory as we embrace, should cling fondly to those
parts which we deem unsound and unphilosophical. They
have accordingly selected the distinctness of the periods when
the antagonist forces are developed, as a principle peculiarly
worthy of implicit faith. For this reason they have declined

Ch. XII.]

OF THE ANTAGONIST POWERS.

197

making any strenuous effort to account for those violations of
continuity in the series of geological phenomena which are
exhibited in large but limited regions ; and. which we have
hinted may admit of explanation by the shifting of the vol-
canic foci, without the necessity of calling in to our aid any
hypothetical eras of convulsion.

In the Oriental cosmogonies, as we have seen, both the
physical and moral worlds were represented to be subject to
gradual deterioration, until a crisis arrived when they were
annihilated, or reverted to a state of chaos ; — there had been
alternating periods of tranquillity and disorder — an endless
vicissitude of destructions and renovations of the globe.

In the spirit of this antique philosophy, some modern geo-
logists conceive that nature, after long periods of repose, is
agitated by fits of " feverish spasmodic energy, during which
her very frame- work is torn asunder*;" — these paroxysms of
internal energy are accompanied by the sudden elevation of
mountain chains^ lC followed by mighty waves desolating
whole regions of the earth-}-"; and, according to some
authors, whole races of organic beings are thus suddenly
annihilated.

It was to be expected that when, in opposition to these fa-
vourite dogmas, we enumerated the subterranean catastrophes
of the last one hundred and forty years, pointing out how
defective were our annals, and called on geologists to multiply
the amount of disturbances arising from this source by myriads
of ages during the existence of successive races of organic
beings, that we should provoke some vehement expostula-
tion. We could not hope that the self-appointed guardians of
Nature's slumber would allow us with impunity thus sud-
denly to intrude upon her rest, or that they would fail to
resent so rude an attempt to rouse her from the torpor into
which she had been lulled by their hypothesis. We were pre-
pared to see our proofs and authorities severely sifted, our

* Prof. Sedgwick, Anrdv. Address, &c. 1831, p. 35. f Ibid.

198 CONSERVATIVE INFLUENCE OF VEGETATION. [Ch. XII.

inferences rigorously scrutinized; but we never supposed it
possible that our adversaries would set up H as a vast coun-
terpoise to all the agents of destruction," a cause so nugatory
as " the single operation of vegetable life

As it will appear from what we before said, that vegetation
cannot act as an antagonist power amid the mighty agents of
change which are always modifying the surface of the globe,
let us next inquire how far its influence is conservative, — how
far it may retard the levelling power of running water, which
it cannot oppose, much less counterbalance.

It is well known that a covering of herbage and shrubs may
protect a loose soil from being carried away by rain, or even by
the ordinary action of a river, and may prevent hills of loose
sand from being blown away by the wind. For the roots bind
together the separate particles into a firm mass, and the leaves
intercept the rain-water, so that it dries up gradually instead
of flowing off in a mass and with great velocity. The old
Italian hydrographers make frequent mention of the increased
degradation which has followed the clearing away of natural
woods in several parts of Italy. A remarkable example was
afforded in the Upper Val d'Arno, in Tuscany, on the removal
of the woods clothing the steep declivities of the hills by which
that valley is bounded. When the ancient forest laws were
abolished by the Grand Duke Joseph, during the last century,
a considerable tract of surface in the Cassentina (the Clausen-
tinium of the Romans) was denuded, and, immediately, the
quantity of sand and soil washed down into the Arno increased
enormously. Frisi, alluding to such occurrences, observes,
that as soon as the bushes and plants were removed, the waters
flowed off more rapidly, and, in the manner of floods, swept
away the vegetable soil f .

This effect of vegetation is of high interest to the geologist,
when he is considering the formation of those valleys which
have been principally due to the action of rivers. The spaces

* Prof. Sedgwick's Anniv. Address, Feb. 1831, p. 24.
\- Treatise on Rivers and Torrents, p. 5, Garston's translation.

Ch. XII.] CONSERVATIVE INFLUENCE OF VEGETATION. 199

intervening between valleys, whether they be flat or ridgy,
when covered with vegetation, may scarcely undergo the slight-
est waste, as the surface may be protected by the green sward
of grass ; and this may be renewed, in the manner before de-
scribed, from elements derived from rain-water and the atmo-
sphere. Hence, while the river is continually bearing down
matter in the alluvial plain, and undermining the cliffs on each
side of every valley, the height of the intervening rising grounds
may remain stationary.

In this manner a cone of loose scoriae, sand and ashes, such
as Monte Nuovo, may, when it has once become densely clothed
with herbage and shrubs, suffer scarcely any farther dilapida-
tion ; and the perfect state of the cones of hundreds of extinct
volcanos in France, Campania, Sicily, and elsewhere, may
prove nothing whatever, either as to their relative or absolute
antiquity. We may be enabled to infer from the integrity of
such conical hills of incoherent materials, that no flood can
have passed over the countries where they are situated since
their formation ; but the atmospheric action alone in spots
where there happen to be no torrents, and where the surface
was clothed with vegetation, could scarcely in any lapse of
ages have destroyed them.

During a late tour in Spain I was surprized to see a dis-
trict of gently undulating ground in Catalonia, consisting of
red and grey sandstone, and in some parts of red marl,
almost entirely denuded of herbage, while the roots of the pines,
holm oaks, and some other trees were half exposed, as if the
soil had been washed away by a flood. Such is the state of
the forests, for example, between Crista and Vich, and near
San Lorenzo. Being at length overtaken by a violent thunder-
storm, in the month of August, I saw the whole surface, even
the highest levels of some flat-topped hills, streaming with
mud, while on every declivity the devastation of torrents was
terrific. The peculiarities in the physiognomy of the district
were at once explained, and I was taught that in speculating
on the greater effects which the direct action of rain may once

200 EFFECTS OF FORESTS ON CLIMATE. [Ch. XII.

have produced on the surface of certain parts of England, we
need not revert to periods when the heat of the climate was
tropical.

In the torrid zone the degradation of land is generally
more rapid, but the waste is by no means proportioned to
the superior quantity of rain or the suddenness of its fall,
the transporting power of water being counteracted by a
greater luxuriance of vegetation. A geologist who is no
stranger to tropical countries observes, that the softer rocks
would speedily be washed away in such regions, if the nu-
merous roots of plants were not matted together in such a
manner as to produce considerable resistance to the destructive
power of the rains. The parasitical and creeping plants also
entwine in every possible direction so as to render the forests
nearly impervious, and the trees possess forms and leaves best
calculated to shoot off the heavy rains, which when they have
thus been broken in their fall are quickly absorbed by the
ground beneath, or when thrown into the drainage depressions
give rise to furious torrents *.

The felling of forests has been attended, in many countries,
by a diminution of rain, as in Barbadoes and Jamaica f. For
in tropical countries, where the quantity of aqueous vapour in
the atmosphere is very great, but where, on the other hand,
the direct rays of the sun have immense power, any impediment
to the free circulation of air, or any screen which shades the
earth from the solar rays, becomes a powerful cause of humi-
dity, and wherever dampness and cold have begun to be
generated by such causes, the condensation of vapour con-
tinues. The leaves moreover of all plants are alembics, and
some of those in the torrid zone have a remarkable power of
distilling water, thus contributing to prevent the earth from
becoming parched up.

There can be no doubt that the state of the climate, espe-
cially the humidity of the atmosphere, influences vegetation,
and that, in its turn, vegetation reacts upon the climate;
* De la Beche, Geol. Man. p. 184. f Phil. Trans., vol. ii., p. 294.

Ch. XII.] DISTRIBUTION OF AMERICAN FORESTS.

201

but some writers seem to have attributed too much import-
ance to the influence of forests, particularly those of America,
as if they were the primary cause of the moisture of the
climate.

The theory of a modern author on this subject, lc that forests
exist in those parts of America only where the predominant
winds carry with them a considerable quantity of moisture
from the ocean," seems far more rational. In all countries, he
says, <e having a summer heat exceeding 70°, the presence or
absence of natural woods, and their greater or less luxuriance,
may be taken as a measure of the amount of humidity, and of
the fertility of the soil. Short and heavy rains, in a warm
country, will produce grass, which, having its roots near the
surface, springs up in a few days, and withers when the moisture
is exhausted ; but transitory rains, however heavy, will not
nourish trees, because, after the surface is saturated with water,
the rest runs off, and the moisture lodged in the soil neither
sinks deep enough, nor is in sufficient quantity, to furnish the
giants of the forest with the necessary sustenance. It may be
assumed, that twenty inches of rain falling moderately, or at
intervals, will leave a greater permanent supply in the soil than
forty inches falling, as it sometimes does in the torrid zone, in
as many hours *."

" In all regions," he continues, f< where ranges of moun-
tains intercept the course of the constant or predominant
winds, the country on the windward side of the mountains
will be moist, and that on the leeward dry, and hence
parched deserts will generally be found on the west side
of countries within the tropics, and on the east side of those
beyond them, the prevailing winds in these cases being gene-
rally in opposite directions. On this principle, the position of
forests in North and South America may be explained. Thus,
for example, in the region within the thirtieth parallel, the
moisture swept up by the trade-wind from the Atlantic is pre-

* Maelaren, Art. America, Encyc, Britaimica.

#02 INFLUENCE OF MAN IN MODIFYING [Ch. XII.

cipitated in part upon the mountains of Brazil, which are but
low and so distributed as to extend far into the interior. The
portion which remains is borne westward, and, losing a little as
it proceeds, it is at length arrested by the Andes, where it falls
down in showers on their summits. The aerial current, now
deprived of all the humidity with which it can part, arrives in
a state of complete exsiccation at Peru, where, consequently,
no rain falls. In the same manner the Ghauts in India, a
chain only three or four thousand feet high, intercept the whole
moisture of the atmosphere, having copious rains on their
windward side, while on the other the weather remains clear
and dry. The rains in this case change regularly from the
west side to the east, and vice versa, with the monsoons. But
in the region of America, beyond the thirtieth parallel, the
Andes serve as a screen to intercept the moisture brought
by the prevailing winds from the Pacific Ocean ; rains are
copious on their summits, and in Chili on their western decli-
vities ; but none falls on the plains to the eastward, except
occasionally when the wind blows from the Atlantic*."

We have been more particular in explaining these views,
because they appear to us to place in a true light the depend-
ence of vegetation on climate, notwithstanding the reciprocal
action which each exerts on the other, the humidity being
increased, and more uniformly diffused throughout the year,
by the gradual spreading of wood.

Before concluding this chapter, we must offer a few obser-
vations on the influence of man in modifying the physical
geography of the globe, for we must class his agency among
the powers of organic nature.

The modifications of the surface, resulting from human
agency, are only on a considerable scale when we have obtained
so much knowledge of the working of the laws of nature as to
be able to use them as instruments to effect our purposes. We

* Maclaren, ibid., where the position of the American forests, in accordance
with this theory, is laid down in a map.

Ch. XII.] THE PHYSICAL GEOGRAPHY OF THE GLOBE. 203

must command nature by obeying her laws, according to the
saying of the philosopher, and for this reason we can never
materially interfere with any of the great changes which either
the aqueous or igneous causes are bringing about on the earth.
In vain would the inhabitants of Italy strive to prevent the
tributaries of the Po and Adige from bearing down, annually,
an immense volume of sand and mud from the Alps and Apen-
nines ; in vain would they toil to re-convey to the mountains
the mass torn from them year by year, and deposited in the
form of sediment in the Adriatic. But they have, never-
theless, been able to vary the distribution of this sediment over
a considerable area, by embanking the rivers, and preventing
the sand and mud from being spread, by annual inundations,
over the plains.

We have explained how the form of the delta of the Po has
been altered by this system of embankment, and how much
more rapid, in consequence of these banks, have been the ac-
cessions of land at the mouths of the Po and Adiffe within
the last twenty centuries. There is a limit, however, to these
modifications, since the danger of floods augments with the
increasing height of the river-beds, while the expense of main-
taining the barrier is continually enhanced, as well as the dif-
ficulty of draining the low surrounding country.

In the Ganges, says Major R. H, Colebrooke, no sooner is
a slight covering of soil observed on a new sand-bank, than the
island is cultivated ; water-melons, cucumbers, and mustard,
become the produce of the first year, and rice is often seen
growing near the water's edge, where the mud is in large
quantity. Such islands may be swept away before they have
acquired a sufficient degree of stability to resist permanently
the force of the stream ; but if, by repeated additions of soil,
they acquire height and firmness, the natives take possession,
and bring over their families, cattle and effects. They choose
the highest spots for the sites of villages, where they erect
their dwellings with as much confidence as they would do on
the main land; for although the foundation is sandy, the

204

INFLUENCE OF MAN IN MODIFYING

[Gh. XII.

uppermost soil being interwoven with the roots of grass and
other plants, and hardened by the sun, is capable of with-
standing all attacks of the river. These islands often grow to
a considerable size, and endure for the lives of the new pos-
sessors, being only at last desti'oyed by the same gradual
process of undermining and encroachment to which the banks
of the Ganges are subject *.

If Bengal were inhabited by a nation more advanced in
opulence and agricultural skill, they might, perhaps, succeed
in defending these possessions against the ravages of the stream
for much longer periods ; but no human power could ever
prevent the Ganges, or the Mississippi, from making and
unmaking islands. By fortifying one spot against the set of
the current, its force is only diverted against some other point;
and, after a vast expense of time and labour, the property of
individuals may be saved, but no addition would thus be made
to the sum of productive land. It may be doubted, whether
any system could be devised so conducive to national wealth,
as the simple plan pursued by the peasants of Hindostan, who,
wasting no strength in attempts to thwart one of the great
operations of nature, permit the alluvial surface to be per-
petually renovated, and find their losses in one place com-
pensated in some other, so that they continue to reap an
undiminished harvest from a virgin soil.

To the geologist, the Gangetic islands, and their migratory
colonies, may present an epitome of the globe as tenanted by
man. For during every century we cede some territory which
the earthquake has sunk, or the volcano has covered by its fiery
products, or which the ocean has devoured by its waves. On
the other hand, we gain possession of new lands, which rivers,
tides, or volcanic ejections have formed, or which subterranean
causes have upheaved from the deep. Whether the human
species will outlast the whole, or a great part of the continents
and islands now seen above the waters, is a subject far beyond
the reach of our conjectures ; but thus much may be inferred

* Asiatic Trans., vol. vii.

Ch. XII.] THE PHYSICAL GEOGRAPHY OF THE GLOBE.

205

from geological data, — that if such should be its lot, it will be
no more than has already fallen to pre-existing species, some of
which have, ere now, outlived the form and distribution of
land and sea which prevailed at the era of their birth.

We have before shown, when treating of the excavation of
new estuaries in Holland by inroads of the ocean, as also of
the changes on our own coasts, that although the conversion of
sea into land by artificial labours may be great, yet it must
always be in subordination to the great movements of the tides
and currents. If, in addition to the assistance obtained by
parliamentary grants for defending Dunwich from the waves,
all the resources of Europe had been directed to the same
end, the existence of that port might possibly have been
prolonged for many centuries. But, in the meantime, the
current would have continued to sweep away portions from the
adjoining cliffs on each side, rounding off the whole line of coast
into its present form, until at length the town must have pro-
jected as a narrow promontory, becoming exposed to the
irresistible fury of the waves.

It is scarcely necessary to observe, that the control which
man can exert over the igneous agents is less even than
that which he may obtain over the aqueous. He cannot
modify the upheaving or depressing force of earthquakes, or
the periods or degree of violence of volcanic eruptions ; and on
these causes the inequalities of the earth's surface, and, con-
sequently, the shape of the sea and land, appear mainly to
depend. The utmost that man can hope to effect in this re-
spect, is occasionally to divert the course of a lava-stream, and
to prevent the burning matter, for a season at least, from over-
whelming a city, or other fruit of human industry.

No application, perhaps, of human skill and labour tends so
greatly to vary the state of the habitable surface, as that em-
ployed in the drainage of lakes and marshes, since not only the
stations of many animals and plants, but the general climate
of a district, may thus be modified. It is also a kind of alter-
ation to which it is difficult, if not impossible, to find anything

206

INFLUENCE OF MAN IN MODIFYING

[Ch. XII.

analogous in the agency of inferior beings. For we ought
always, before we decide that any part of the influence of man
is novel and anomalous, carefully to consider all the powers of
other animate agents which may be limited or superseded by
him. Many who have reasoned on these subjects seem to
have forgotten that the human race often succeeds to the dis-
charge of functions previously fulfilled by other species ; a
topic on which we have already offered some hints, when ex-
plaining how the distribution and numbers of each species are
dependent on the state of contemporary beings.

Suppose the growth of some of the larger terrestrial plants,
or, in other words, the extent of forests, to be diminished by
man, and the climate to be thereby modified, it does not follow
that this kind of innovation is unprecedented. It is a change
in the state of the vegetation, and such may often have been
the result of the entrance of new species into the earth. The
multiplication, for example, of certain insects in parts of Ger-
many, during the last century, destroyed more trees than man,
perhaps, could have felled during an equal period.

It is a curious fact, to which we shall again advert, that
the sites of many European forests., cut down since the time of
the Romans, have become peat-mosses ; and thus a permanent
change has been effected in these regions. But other woods,
blown down by winds, in the same countries, have also become
peat-bogs ; so that, although man may have accelerated some-
what the change, yet it may be doubted whether other animate
and inanimate causes might not, without his interference, have
produced similar results. The atmosphere of our latitudes
may have been slowly and insensibly cooling down since the
ancient forests began to grow, and the time may have arrived
when slight accidents were sufficient to cause the decrease of
trees, and the usurpation of their site by other plants.

We do not pretend to decide how far the power of man, to
modify the surface, may differ in kind or degree from that of
other living beings, but we suspect that the problem is more
complex than has been imagined by many who have speculated

Ch.XIL] THE PHYSICAL GEOGRAPHY OF THE GLOBE. 207

on such topics. If new land be raised from the sea, the great-
est alteration in its physical condition, which could ever arise
from the influence of organic beings, would probably be pro-
duced by the first immigration of terrestrial plants, whereby the
tract would become covered with vegetation. The change next
in importance would seem to be when animals enter, and modify
the proportionate numbers of certain species of plants. If
there be any anomaly in the intervention of man, in farther
varying the relative numbers in the vegetable kingdom, it may
not so much consist in the kind or absolute quantity of altera-
tion, as in the circumstance that a single species, in this case,
would exert, by its superior power and universal distribution,
an influence equal to that of hundreds of other terrestrial
animals.

If we inquire whether man, by his direct removing power,
or by the changes which he may give rise to indirectly, tends,
upon the whole, to lessen or increase the inequalities of the
earth's surface, we shall incline, perhaps, to the opinion that
he is a levelling agent. He conveys upwards a certain quan-
tity of materials from the bowels of the earth in mining
operations ; but, on the other hand, much rock is taken
annually from the land, in the shape of ballast, and afterwards
thrown into the sea, whereby, in spite of prohibitory laws,
many harbours, in various parts of the world, have been blocked
up. We rarely transport heavy materials to higher levels,
and our pyramids and cities are chiefly constructed of stone
brought down from more elevated situations. By ploughing
up thousands of square miles, and exposing a surface for
part of the year to the action of the elements, we assist the
abrading force of rain, and destroy the conservative effects of
vegetation.

But the aggregate force exerted by man is truly insignificant,
when we consider the operations of the great physical causes,
whether aqueous or igneous, in the inanimate world. If all the
nations of the earth should attempt to quarry away the lava
which flowed during one eruption from the Icelandic volcanoes

208

INFLUENCE OF MAN.

[Ch. XII.

in 1783 and the two following years, and should attempt to
consign it to the deepest abysses of the ocean, wherein it might
approach most nearly to the profundities from which it rose in
the volcanic vent, they might toil for thousands of years before
their task was accomplished. Yet the matter borne down by
the Ganges and Burrampooter, in a single year, probably
exceeds, in weight and volume, the mass of Icelandic lava
produced by that great eruption.

CHAPTER XIII.

Effects produced by the action of animal and vegetable life on the material con-
stituents of the earth's crust — Imbedding of organic remains in deposits on
emerged land — Growth of Peat— Peat abundant in cold and humid climates —
Site of many ancient forests in Europe now occupied by peat — Recent date of
many of these changes — Sources of Bog Iron-ore — Preservation of animal sub-
stances in Peat — Causes of its antiseptic property — Miring of quadrupeds

Bursting of the Solway Moss — Bones of herbivorous quadrupeds found in 'peat
— Imbedding of animal remains in Caves and Fissures — Formation of bony-
breccias — Human bones and pottery intermixed with the remains of extinct
quadrupeds in caves in the South of France — Inferences deducible from such
associations.

We now come to the second subdivision of the inquiry ex-
plained in the preceding chapter, — the consideration of the
permanent modifications produced in the material constituents
of the earth's crust, by the action of animal and vegetable life.

New mineral compounds, such as might never have existed
in this globe but for the action of the powers of vitality, are
annually formed, and made to enter into deposits accumu-
lated both above and beneath the waters. Although we
can neither explain nor imitate the processes of animal and
vegetable life whereby those substances are produced, yet we
can investigate the laws by virtue of which organic matter be-
comes imbedded in new strata, — sometimes imparting to them
a peculiar mineral composition, — sometimes leaving durable im-
pressions and casts of the forms of animate beings in rocks,
so as to modify their structure and appearance.

It has been well remarked by M. Constant Prevost, that the
effects of geological causes are divisible into two great classes j
those produced on the surface during the immersion of land
beneath the waters, and those which take place after its emer-
sion. Agreeably to this classification we shall consider, first,
in what manner animal and vegetable remains become included

and preserved in solid deposits on emerged land, or that part
Vol. II. p

210 ORGANIC REMAINS IN PEAT. [Ch. XIII.

of the surface which is not permanently covered by water,
whether of the sea or lakes ; secondly, the manner in which
organic remains become imbedded in sub-aqueous deposits.

Under the first division we shall treat of the following
topics : — 1st, the growth of peat, and the preservation of
vegetable and animal remains therein ; — 2ndly, the preserva-
tion of animal remains in stalactite, and in the mud of caves
and fissures ; — 3dly, the burying of organic remains in allu-
vium and the ruins of land- slips ; — 4thly, of the same in
blown sand ; — Sthly, of the same in volcanic ejections, and
alluvions composed of volcanic productions.

The growth of Peat and the preservation of Vegetable and
Animal Remains therein.

The generation of peat, when not completely under water,
is confined to moist situations, where the temperature is low,
and where vegetables may decompose without putrifying. It
may consist of any of the numerous plants which are capable
of growing in such stations : but a species of moss {sphagnum
palustre) constitutes a considerable part of the peat found in
marshes of the north of Europe ; this plant having the pro-
perty of throwing up new shoots in its upper part, while its
lower extremities are decaying *. Reeds, rushes, and other
aquatic plants may usually be traced in peat, and their
organization is often so entire, that there is no difficulty in
discriminating the distinct species.

In general, says Sir H. Davy, one hundred parts of dry peat
contain from sixty to ninety-nine parts of matter destructible
by fire, and the residuum consists of earths usually of the same
kind as the substratum of clay, marl, gravel, or rock on which
they are found, together with oxide of iron. " The peat of the
chalk counties of England," observes the same writer, "con-
tains much gypsum ; but I have found very little in any

* For a catalogue of the plants which contribute to the generation of peat, see
Dr. Rennie on Peat, p. 171—178. Dr. Macculloch's Western Isles, yol.i.p. 129.

Ch. XIII.] AREA COVERED BY PEAT. 211

specimens from Ireland or Scotland, and in general these peats
contain very little saline matter*." From the researches of
Dr. Macculloch, it appears that peat is intermediate between
simple vegetable matter and lignite, the conversion of peat
to lignite being gradual, and being brought about in a great
lapse of time by the prolonged action of water *f\

Peat is sometimes formed on a declivity in mountainous
regions where there is much moisture, but in such situations it
rarely if ever exceeds four feet in thickness. In bogs, and in
low grounds into which alluvial peat is drifted, it is found
forty feet thick and upwards, but in such cases it generally
owes one-half of its volume to the water which it contains. It
nas seldom, if ever, been discovered within the tropics, and it
rarely occurs in the valleys even in the south of France and
Spain. It abounds more and more in proportion as we ad-
vance farther from the equator, and becomes not only more
frequent but more inflammable in northern latitudes £ ; the
cause of which may probably be that the carbonic acid and
hydrogen, which are the most inflammable parts, do not
readily assume the gaseous form in a cold atmosphere.

There is a vast extent of surface in Europe covered with
peat, which in Ireland is said to extend over a tenth of the
whole island. One of the mosses on the Shannon is described
by Dr. Boates to be fifty miles long, by two or three broad ;
and the great marsh of Montoire, near the mouth of the
Loire, is mentioned by Blavier as being more than fifty leagues
in circumference. It is a curious and well-ascertained fact that
many of these mosses of the north of Europe occupy the place
of immense forests of pine and oak, which have many of them
disappeared within the historical era. Such changes are
brought about by the fall of trees and the stagnation of water,
caused by their trunks and branches obstructing the free
drainage of the atmospheric waters, and giving rise to a marsh.
In a warm climate such decayed timber would immediately be

* Irish Bog Reports, p. 209. f System of Geology, vol. ii. p. 353.
$ Rev. Dr. Rennie, ibid. p. 260.

P 2

CONVERSION OF FORESTS

tCh. XIII.

removed by insects, or by putrefaction ; but, in the cold tem-
perature now prevailing in our latitudes, many examples are
recorded of marshes originating in this source. Thus, in Mar
forest, in Aberdeenshire, large trunks of Scotch fir, which had
fallen from age and decay, were soon immured in peat formed
partly out of their perishing leaves and branches, and in part
from the growth of other plants. We also learn that the
overthrow of a forest by a storm, about the middle of the
seventeenth century, gave rise to a peat moss, near Lochbroom.,
in Ross-shire, where, in less than half a century after the fall of
the trees, the inhabitants dug peat*. Dr. Walker mentions
a similar change when, in the year 1756, the whole wood of
Drumlanrig was overset by the wind. Such events explain the
occurrence, both in Britain and on the continent, of mosses
where the trees are all broken within two or three feet of the
original surface, and where their trunks all lie in the same
direction f .

Nothing is more common than the occurrence of buried trees
at the bottom of the Irish peat-mosses, as also in most of those
of England, France, and Holland ; and they have been so often
observed with parts of their trunks standing erect, and with
their roots fixed to the sub-soil, that no doubt can be enter-
tained of their having generally grown on the spot. They con-
sist for the most part of the fir, the oak, and the birch ; where
the sub-soil is clay, the remains of oak are the most abundant ;
where sand is the substratum, fir prevails. In the marsh of
Curragh, in the Isle of Man, vast trees are discovered standing
firm on their roots, though at the depth of eighteen or twenty
feet below the surface. Some naturalists have desired to refer
the imbedding of timber in peat mosses to aqueous trans-
portation, since rivers are well known to float wood into
lakes ; but the facts above mentioned show that, in numerous
instances, such an hypothesis is inadmissible. It has more-
over been observed that in Scotland, as also in many parts of
the continent, the largest trees are found in those peat mosses

* Dr. Reunie's Essays, p. 65. | Ibid. p. 30.

Ch. XIII.]

INTO PEAT-MOSSES.

213

which lie in the least elevated regions, and that the trees are
proportionably smaller in those which lie at higher levels ;
from which fact De Luc and Walker have both inferred that
the trees grew on the spot, for they would naturally attain a
greater size in lower and warmer levels, The leaves also, and
fruits of each species, are continually found immersed in the
moss along with the parent trees, as, for example, the leaves
and acorns of the oak, the cones and leaves of the fir, and the
nuts of the hazel.

Sometimes, in the same bog, a stratification is observed of
different kinds of wood, oak being found in the lowermost
stratum, and birch and hazel in a second bed above. Some-
times still higher, a stratum, containing alder with the twigs of
the bog myrtle (Myrica galce), have been found * ; the suc-
cession of strata, in this instance, indicating a gradual conver-
sion of a dry tract into a swamp, and lastly a peat-moss.

The durability of pine- wood, which in the Scotch peat-mosses
exceeds that of the birch and oak, is due to the great quantity
of turpentine which it contains, and which is so abundant that
the fir- wood from bogs is used by the country people, in parts
of Scotland, in the place of candles. Such resinous plants,
observes Dr. Macculloch, as fir, would produce a fatter coal
than oak, because the resin itself is converted into bitumen f .

In Hatfield-moss, which appears clearly to have been a
forest eighteen hundred years ago, fir-trees have been found
ninety feet long, and sold for masts and keels of ships ; oaks
have also been discovered there above one hundred feet long.
The dimensions of an oak from this moss are given in the
Philosophical Transactions, No. 275, which must have been
larger than any tree now existing in the British dominions.

In the same moss of Hatfield, as well as in that of Kincar-
dine and several others, Roman roads have been found covered
to the depth of eight feet by peat. All the coins, axes, arms, and
other utensils found in British and French mosses, are also
Roman ; so that a considerable portion of the European peat-

* Lib. Ent. Know., Timber Trees, p. 32, f Syst. of Geol., vol. ii.,p. 356.

£14 FORESTS CONVERTED INTO PEAT-BOGS. [Ch. XIII.

bogs are evidently not more ancient than the age of Julius
Cassar. Nor can any vestiges of the ancient forests described
by that general, along the line of the great Roman way in
Britain, be discovered, except in the ruined trunks of trees in
peat.

De Luc ascertained that the very site of the aboriginal
forests of Hircinia, Semana, Ardennes, and several others, are
now occupied by mosses and fens ; and a great part of these
changes have, with much probability, been attributed to the
strict orders given by Severus, and other emperors, to destroy
all the wood in the conquered provinces. Several of the
British forests, however, which are now mosses, were cut at
different periods by order of the English parliament, because
they harboured wolves or outlaws. Thus the Welsh woods
were cut and burnt in the reign of Edward I. ; as were. many
of those in Ireland by Henry II., to prevent the natives from
harbouring in them and harassing his troops.

It is curious to reflect, that considerable tracts have by these
accidents been permanently sterilized, and that during a period
when civilization has been making great progress, large areas
in Europe have, by human agency, been rendered less capable
of administering to the wants of man. Rennie observes with
truth, that in those regions alone which the Roman eagle
never reached — in the remote circles of the German empire, in
Poland and Prussia, and still more in Norway, Sweden, and
the vast empire of Russia — can we see what Europe was before
it yielded to the power of Rome*. Desolation now reigns
where stately forests of pine and oak once flourished, such
as might now have supplied all the navies of Europe with
timber.

At the bottom of peat mosses there is sometimes found a cake,
or " pan," as it is termed, of oxide of iron, and the frequency of
bog iron-ore is familiar to the mineralogist. The oak which
is so often found dyed black in peat, owes its colour to the
same metal. From what source the iron is derived is by no

* Essays, &c, p. 74.

Ch. XIII.]

HUMAN REMAINS IN PEAT.

means obvious, since we cannot in all cases suppose that it
has been precipitated from the waters of mineral springs.
According to Fourcroy there is iron in all compact wood, and
it is the cause of one-twelfth part of the weight of oak.
The heaths (Ericas) which flourish in a sandy, ferruginous soil,
are said to contain more iron than any other vegetable.

It has been suggested that iron, being soluble in acids, may
be diffused through the whole mass of vegetables, when they
decay in a bog, and may, by its superior specific gravity, sink
to the bottom, and be there precipitated, so as to form bog
iron-ore ; or where there is a subsoil of sand or gravel, it may
cement them into ironstone or ferruginous conglomerate *.

One interesting circumstance attending the history of peat-
mosses is the high state of preservation of animal substances
buried in them for periods of many years. In June, 1747,
the body of a woman was found six feet deep, in a peat-
moor in the Isle of Axholm, in Lincolnshire. The antique
sandals on her feet afforded evidence of her having been buried
there for many ages ; yet her nails, hair, and skin, are described
as having shown hardly any marks of decay. In a turbary on
the estate of the Earl of Moira, in Ireland, a human body
Was dug up, a foot deep in gravel, covered with eleven feet
of moss ; the body was completely clothed, and the garments
seemed all to be made of hair. Before the use of wool was
known in that country, the clothing of the inhabitants was
made of hair, so that it would appear that this body had
been buried at that early period ; yet it was fresh and unim-
paired f. In the Philosophical Transactions, we find an
example recorded of the bodies of two persons having been
buried in moist peat, in Derbyshire, in 1674, about a yard
, deep, which were examined twenty-eight years and nine months,
afterwards ; " the colour of their skin was fair and natural,
their flesh soft as that of persons newly dead $**

* Dr. Rennie, Essays, &c, p. 347.
f lb. p. 521, where several other instances are referred to.
J Phil. Trans., vol. xxxviii.; 1734.

ANIMAL REMAINS IN PEAT.

[Ch. XIII.

Among other analogous facts we may mention, that in dig-
ging a pit for a well near Dulverton, in Somersetshire, many-
pigs were found in various postures, still entire. Their shape
was well preserved, the skin, which retained the hair, having
assumed a dry, membranous appearance. Their whole sub-
stance was converted into a white, friable, laminated, inodorous,
and tasteless substance ; but which, when exposed to heat,
emitted an odour precisely similar to broiled bacon *.

We naturally ask whence peat derives this antiseptic pro-
perty ? It has been attributed by some to the carbonic and
gallic acids which issue from decayed wood, as also to the pre-
sence of charred wood in the lowest strata of many peat-mosses,
for charcoal is a powerful antiseptic, and capable of purifying
water already putrid. Vegetable gums and resins also may
operate in the same way f.

The tannin occasionally present in peat is the produce, says
Dr. Macculloch, of tormentilla, and some other plants, but
the quantity he thinks too small, and its occurrence too casual,
to give rise to effects of any importance. He hints that the
soft parts of animal bodies, preserved in peat-bogs, may have
been converted into adipocire by the action of water merely ;
an explanation which appears clearly applicable to some of
the cases above enumerated £.

The manner, however, in which peat contributes to preserve,
for indefinite periods, the harder parts of terrestrial animals,
is a subject of more immediate interest to the geologist. There
are two ways in which animals become occasionally buried in
the peat of marshy grounds ; they either sink down into the
semifluid mud, underlying a turfy surface, upon which they
have rashly ventured, or, at other times, a bog " bursts," in
the manner described in a preceding chapter, and animals may
be involved in the peaty alluvium.

In the extensive bogs of Newfoundland, cattle are sometimes
found buried with their heads only and neck above ground,

* Dr, Rennie, Essays, &e.,p. 521. f Ibid., p. 531.

J Syst. of Geol., vol. ii., pp. 340—346.

Ch. XIII.]

BURSTING OF SOLWAY MOSS.

217

and after having remained for days in this situation, they
have been drawn out by ropes and saved. In Scotland,
also, cattle venturing on the " quaking moss" are often mired,
or " laired," as it is termed ; and in Ireland, Mr. King asserts
that the number of cattle which are lost in sloughs is quite
incredible *.

The description given of the Solway moss will serve to
illustrate the general character of these boggy grounds. That
moss, observes Gilpin, is a flat area, about seven miles in cir-
cumference, situated on the confines of England and Scot-
land. Its surface is covered with grass and rushes, presenting
a dry crust and a fair appearance ; but it shakes under the least
pressure, the bottom being unsound and semifluid. The ad-
venturous passenger, therefore, who sometimes in dry seasons
traverses this perilous waste, to save a few miles, picks his
cautious way over the rushy tussocks as they appear before
him, for here the soil is firmest. If his foot slip, or if he
venture to desert this mark of security, it is possible he may
never more be heard of.

" At the battle of Solway, in the time of Henry VIII. (1542),
when the Scotch army, commanded by Oliver Sinclair, was
routed, an unfortunate troop of horse, driven by their fears,
plunged into this morass, which instantly closed upon them.
The tale was traditional, but it is now authenticated ; a man
and horse, in complete armour, having been found by peat-
diggers, in the place where it was always supposed the affair
had happened. The skeleton of each was well preserved, and
the different parts of the armour easily distinguished f

This same moss, on the 16th of December, 1772, having
been filled with water during heavy rains, rose to an unusual
height and then burst. A stream of black half- consolidated
mud began at first to creep over the plain, resembling, in the
rate of its progress, an ordinary lava current. No lives were
lost, but the deluge totally overwhelmed some cottages, and

* Phil. Trans., vol. xv., p. 949.
+ Observations on Picturesque Beauty, &c, 1772.

BURSTING OF PEAT-MOSSES.

[Ch. XIII.

covered four hundred acres. The highest parts of the original
moss subsided to the depth of about twenty-five feet, and the
height of the moss, on the lowest parts of the country which it
invaded, was at least fifteen feet.

A recent inundation in Sligo (January, 1831) affords
another example of this phenomenon. After a sudden thaw
of snow the bog between Bloomfield and Geevah gave way,
and a black deluge, carrying with it the contents of a hundred
acres of bog, took the direction of a 'small stream, and rolled
on with the violence of a torrent, sweeping along heath, timber,
mud, and stones, and overwhelming many meadows and arable
land. On passing through some boggy land the flood swept
out a wide and deep ravine, and part of the road leading from
Bloomfield to St. James's Well was completely carried away
from below the foundation for the breadth of two hundred
yards.

The antlers of large and full-grown stags are amongst the
most common and conspicuous remains of animals in peat.
They are not horns which have been shed, for portions of the
skull are found attached, proving that the whole animal
perished. Bones of the ox, hog, horse, sheep, and other
herbivorous animals, also occur ; and in Ireland and the Isle of
Man, skeletons of a gigantic elk ; but no remains have been
met with belonging to those extinct quadrupeds of which the
living congeners inhabit warmer latitudes, such as the ele-
phant, rhinoceros, hippopotamus, hyaena, and tiger, though
these are so common in superficial deposits of silt, mud, sand, or
stalactite, in various localities throughout Great Britain. Their
absence seems to imply that they had ceased to live before the
atmosphere of this part of the world acquired that cold and
humid character which favours the growth of peat.

From the facts before mentioned,, that mosses occasionally
burst, and descend in a fluid state to lower levels, it will
readily be seen that lakes and arms of the sea may occasionally
become the receptacles of drift-peat. Of this accordingly
there are numerous examples, and hence the alternations of

Ch.XIII.J ANIMAL REMAINS IN CAVES. £19

clay and sand with different deposits of peat so frequent on
some coasts, as on those of the Baltic and German Ocean.
We are informed by Deguer that remains of ships, nautical
instruments, and oars, have been found in many of the Dutch
mosses; and Gerard, in his History of the Valley of the
Somme, mentions that in the lowest tier of that moss was
found a boat loaded with bricks, proving that these mosses
were at one period navigable lakes and arms of the sea, as
were also many mosses on the coast of Picardy, Zealand, and
Friesland, from which soda and salt are procured *, The
canoes, stone hatchets, and stone arrow-heads, found in peat
in different parts of Great Britain, lead to similar conclusions,
— but these will more properly be considered when we treat
of subaqueous phenomena.

Imbedding of Animal Remains in the Stalactite and Mud of

Caves and Fissures.

We explained in the former volume how vast fissures have
been formed from time to time by earthquakes, and suggested
that the continual percolation of acidulous waters through
rocks of limestone might have enlarged these fissures into
caverns. We shall now consider in what manner the remains
of animals may become preserved in rents and cavities, con-
fining ourselves at present to the monuments of events which
are known or can be inferred to have happened within the
human era.

As the same caves and fissures may remain open throughout
periods of indefinite duration, and may become the receptacles
of the remains of species inhabiting a country at very different
epochs, it requires the utmost care to avoid confounding together
the monuments of occurrences of very distinct dates. Dr.
Buckland, in his indefatigable researches into this class of
phenomena, has often guarded with great skill against such
anachronisms, pointing out the comparatively recent preser-

* Eennie on Peat Moss, p. 205.

220

IMBEDDING OF ORGANIC REMAINS

[Ch. XIII.

vation of some organic relics which have become mingled in
a common tomb with those of older date.

Fissures are very common in calcareous rocks, and these
are usually, in the course of ages, filled up in part by small
angular fragments of limestone, which scale off under the
influence of frost and rain. Vegetable earth and land-shells are
washed in at the same time, and the whole mass often becomes
cemented together by calcareous matter dissolved by rain-
water, or supplied by mineral springs. In an uncultivated
country the edges of such fissures are usually overgrown with
bushes, so that herbivorous animals, especially when chased
by beasts of prey, or when carelessly browzing on the shrubs,
are liable to fall in and perish. Of this kind is a fissure still
open in Duncombe Park, in Yorkshire, Avhere the skeletons of
dogs, sheep, goats, deer, and hogs, have been found, lodged
upon different ledges that occur at various depths in a rent of
the rock descending obliquely downwards*.

Above the village of Selside,near Ingleborough in Yorkshire,"
a chasm of enormous but unknown depth occurs in the scar-
limestone, a member of the carboniferous series. " The chasm,"
says Professor Sedgwick, " is surrounded by grassy shelving
banks, and many animals, tempted towards its brink, have
fallen down and perished in it. The approach of cattle is
now prevented by a strong lofty wall, but there can be no
doubt that, during the last two or three thousand years, great
masses of bony breccia must have accumulated in the lower
parts of the great fissure, which probably descends through
the whole thickness of the scar-limestone, to the depth of per-
haps five or six hundred feet i."

A fissure in the limestone of the Coiron, in France, is seen
on the high road between Aubenas and Ville-Dieu, filled
with a breccia, consisting of angular fragments of the rock and
land-shells cemented together. The mode of its formation is

* Bucklandf Reliquiae Diluvianse, p. 55.
f Memoir on the Structure of the Lake Mountains of the North of England,
&c, read before the Geological Society, January 5, 1831.

Ch. XIII. ] IN THE MUD OF CAVES AND FISSURES.

221

admirably illustrated by the rapid growth of a similar deposit
not far distant. At the pass of Escrinet, on the northern
escarpment of the Coiron hills, near Aubenas, a tabular mass
of limestone is seen disintegrating into innumerable angular
fragments, which are transported by the rain to the foot of the
declivity, where they have accumulated at one spot, in a talus
fifty feet in thickness and five hundred yards wide. The upper
part is composed for the most part of loose fragments, on which
numerous land-shells are seen living ; the lower portion is
consolidated by stalagmite into a compact mass which serves
for mill-stones. The calcareous cement has a red tinge, but
not of so deep a colour as most of the Mediterranean breccias*.

By the decomposition of the calcareous rocks near Nice, a
soil is produced of a blood-red colour; and red breccias, con-
sisting of fragments of rock and land-shells cemented together,
are continually forming. If the mountains here were rent by
earthquakes, we might expect the fissures to be gradually filled
with red breccias like those of higher antiquity so celebrated in
many parts of the Mediterranean.

If often happens that fissures communicate with subterranean
caverns, a fact somewhat confirmatory of the views of those
geologists who attribute the origin of limestone caverns in
great part to the movements and dislocations of the strata.
In this case the fissure may serve for ages as a natural pit-fall
to animals passing by, and their bones, with all the earth, sand,
and fragments of rock that fall through these passages, may
be washed down or subside by their own weight, so as to reach
the cavern below where thick deposits may be amassed.

Oftentimes when the bones of animals are strewed alono- the
bottom of fissures or caves which they may have inhabited,
they become covered over with mud infroduced by land-floods,
and are thus preserved from decomposition. Thus on the floor
of many caverns mentioned by Dr. Buckland, in the Mendip
Hills and Derbyshire, sedimentary mud has been left in recent
times during floods.

* I examined this spoi in tlie year 1828, accompanied by Mr, Murchison.

IMBEDDING OF ORGANIC REMAINS

[Ch. XIII.

The same author observed in every cave examined by him
in Germany, a deposit of mud or sand, sometimes with, and
sometimes -without, an intermixture of rolled pebbles and
angular fragments of rock, and having its surface covered
over with a single crust of stalagmite*. In the English
caves he remarked a similar absence of alternations of allu-
vium and stalagmite. On the banks of the Meuse, however, at
Chockier, about two leagues from Liege, a cavern has been re-
cently discovered where there are three distinct beds of stalag-
mite, between each of which occur breccia and mud, mixed with
some quartz pebbles, and the bones of extinct quadrupeds f .

But this exception does not invalidate the generality of the
phenomenon observed by the Professor, and of which we have
as yet seen no satisfactory explanation. The principal cause
we suspect to be, that if several floods pass at different inter-
vals of time through any subterranean passage, the last, if it has
power to drift along fragments of rock, will also tear up any
alternating stalagmitic and alluvial beds that may happen to
have been previously formed. Another cause may be, that in
a country in which torrents and rivers are gradually deepening
their channels, and cutting through masses of cavernous lime-
stone (an excavating process which is most rapid during
epochs of subterranean disturbance, when the levels of a dis-
trict are altered), it will only happen once that the stream will
break into hollows or fissures communicating with a certain
series of caverns. When the erosive action has proceeded
farther, and the river has sunk to a greater depth, the drainage
of the country will be effected in a valley at a level inferior to
that of the caves, and consequently no transported matter will
afterwards be introduced into them.

In the cave of Paviland, called Goat's Hole, on the coast of
Glamorganshire, besides the bones of many extinct animals
which occur in a mass of loam, a modern breccia has been
formed, consisting of earth cemented by stalagmite, and con-

* Rel.Dil.p. 108.
t Journ. de Geolpgie, tome i. p. 286. July, 1830.

Ch. XIII.] IN THE MUD OP CAVES AND FISSURES. ggS

taining marine-shells and birds' bones, all of recent species.
The mouth of this cave is from thirty to forty feet above high-
water mark, being situated in a lofty cliff of limestone, facing
the estuary of the Severn, the waves of which, during great
storms, occasionally dash into it. The left side of a human
skeleton was also found here under a cover of six inches of
earth. In a cavernous aperture leading from the roof of this
cave to the face of the cliff was discovered a bed of brown
earth, apparently derived from dust driven in continually by the
wind ; and in this earth were the bones of various birds, of moles,
water-rats, mice, and fish, and a few land-shells, all clearly the
remains of modern animals. Their presence in this almost
inaccessible spot can only be explained, says Dr. Buckland,
" by referring the bones of birds, moles, rats, and mice, to the
agency of hawks, and the fish-bones to that of sea-gulls. The
land-shells, which are such as live at present on the rock with-
out, may easily have fallen in, Had there been any stalag-
mite uniting these bones into a breccia, they would have
afforded a perfect analogy to the accumulation of modern
birds' bones, by the agency of hawks, at Gibraltar*."

The formation last alluded to occurs in perpendicular fis-
sures at the north extremity of the rock of Gibraltar, where a
reddish calcareous earth, containing numerous bones of small
birds, is in the act of accumulating. Around these fissures a
number of hawks nestle and rear their young in the breeding-
season, and the bones are the remains of their food. Major
Imrie mentions also a concretion in the rocks below King's
Lines, Gibraltar, consisting of pebbles of the prevailing cal-
careous rock, wherein, at a considerable depth under the sur-
face, part of a green glass bottle was found imbedded f.

In a cave of mountain-limestone at Burringdon, in the
Mendip Hills, supposed to have been once used as a place of
sepulture or refuge, human bones have been met with, en-
crusted with stalactite, one of the skulls being filled with this

* BucMand, Reliquiae Diluvianee, p. 93. >f lb. p. 156.

224 HUMAN REMAINS IN CAVES. [Ch. XIII.

substance in the interior *. The state of the bones, says Dr.
Buckland, affords indications of very high antiquity.

The remains of human skeletons have been also found in
the cave of Wokey Hole, near Wells, in the Mendips, dis-
persed through reddish mud and clay, and some of them
united by stalagmite into a firm osseous breccia. " The spot
on which they lie is within reach of the highest floods of the
adjacent river, and the mud in which they are buried is evi-
dently fluviatile j-."

We shall conclude with alluding to some caverns recently
examined in the south of France, in which human bones and
fragments of pottery are described as intermingled in the same
deposits with the remains of extinct mammalia. We may
first mention the cavern of Bize, in the department of Aude,
where M. Marcel de Serres met with a small number of
human bones mixed with those of extinct animals and with
land-shells. They occur in a calcareous stony mass, bound
together by a cement of stalagmite. On examining the same
caverns, M. Tournal found not only in these calcareous beds,
but also in a black mud which overlies a red osseous mud,
several human teeth, together with broken angular fragments
of a rude kind of pottery, and also marine and terrestrial shells
of our own epoch. The teeth preserve their enamel, but the
fangs are so much altered as to adhere strongly to the tongue.
Of the terrestrial shells thus associated with the bones and
pottery, the most common are Cyclostoma elegans, Bulimus
decollatus, Helix nemoralis and H. nitida. Among the ma-
rine are found Pecten jacobaeus, Mytilus edulis, and Natica
mille-punctata, all of them eatable kinds. Bones of quadru-
peds were found in the same mass belonging to three new
species of the deer kind, an extinct bear ( Ursus arcto'ideus),
besides the wild bull (Bos urus), formerly a native of Germany J.
In the same part of France, M. de Christol has found in

* Buckland, Reliquiae, pi 164. -j- lb. p. 165.

X M. Marcel de Serres, Geognosie des Terrains Tertiaires, p. 64. Introduction.

Ch. XIII.]

HUMAN REMAINS IN CAVES.

caverns in a tertiary limestone at Pondres and Souvignargues,
situated two leagues north of Lunel-viel, (department of
Herault,) human bones and pottery confusedly mixed with the
remains of the rhinoceros, bear, hyaena, and many other ter-
restrial mammifers. They were imbedded in an alluvial mud,
of the solidity of calcareous tufa, and containing some flint
pebbles and fragments of the limestone of the country.
Beneath this mixed accumulation, which sometimes attained
a thickness of thirteen feet, is the original floor of the cavern,
about a foot thick, covered with bones and the dung of animals
{album gr cecum), in a sandy and tufaceous cement.

The human bones in these caverns of Pondres and SouviV-
nargues were found, upon a careful analysis, to have parted
with their animal matter to as great a degree as those of the
hyaena which accompany them, and are equally brittle, and
adhere as strongly to the tongue.

In order to compare the degree of alteration of these bones
with those known to be of high antiquity, M. Marcel de
Serres, and M. Ballard, Chemist of Montpellier, procured
some from a Gaulish sarcophagus in the plain of Lunel, sup-
posed to have been buried for fourteen or fifteen centuries at
least. In these the cellular tissue was empty, but they were
more solid than fresh bones. They did not adhere to the
tongue in the same manner as those of the caverns of Bize
and Pondres, yet they had lost at least three-fourths of their
original animal matter.

The superior solidity of the Gaulish bones to those in a
fresh skeleton is a fact in perfect accordance with the observa-
tions made by Mr. Mantell on bones taken from a Saxon
tumulus, near Lewes.

Let us now consider what conclusions are deducible from
the important facts above enumerated. Must we infer that
man and these extinct quadrupeds were contemporaneous in-
habitants of the south of France at some former epoch ? We
should unquestionably have arrived at this conclusion if the
bones had been found in an undisturbed stratified deposit of

Vol. II. Q

22G

HUMAN REMAINS IN CAVES.

[Ch. XTII.

subaqueous origin, especially if it contained shells in regular
layers like that of North-Cliff in Yorkshire, described by
Mr. Vernon, from which we learn that the mammoth coexisted
with thirteen species of our living British land and fresh-water
testacea % But we must hesitate before we draw analogous
inferences from evidences so equivocal as that afforded by the
mud, stalagmites and breccias of caves, where the signs of
successive deposition are wanting.

No one will maintain that man, the hyaena, and the bear,
were at once joint tenants of these caverns ; and if it be neces-
sary to assume that the mud and pebbles were washed into
their present position by floods, the same inundations might
possibly have caught up the bones lying in more ancient de-
posits, and thus have mingled the whole together in the same
mass.

More than ordinary caution is required in reasoning on the
occurrence of human remains and works of art in alluvial
deposits, since the chances of error are much greater than when
we have the fossil bones of the inferior animals only under
consideration. For the floor of caves has usually been disturbed
by the aboriginal inhabitants of each country, who have used
such retreats for dwelling places, or for concealment, or sepul-
ture. In such spots have treasures been often buried in periods
of disturbance, or diligently sought for in times of tranquillity.
The excavations made in Sicily for treasure- trove, in places
where no money was ever buried, are believed to exceed in
number all the spots in which coin was ever hid during the
wars between the Saracens and Christians.

Dr. Buckland, in speaking of the cave of Paviland, before
mentioned, states that the entire mass through which the bones
were dispersed, appeared to have been disturbed by ancient
diggings, so that the remains of extinct animals had, in that
instance, actually become mixed with the recent bones and
shells. In the same cave he found a human skeleton, and the
remains of recent testacea of eatable species, which may have

* See ante, vol. i. p. 96.

Ch. XIII.] HUMAN REMAINS IN CAVES. 227

been carried in by man. The same observation is applicable
to the marine testacea of the cavern of Bize, and we suspect
the whole phenomena to be very analogous. ■

To decide whether certain relics have been introduced by
man, or natural causes, into masses of transported materials,
must almost always be a task of some difficulty, especially
where all the substances, organic and inorganic, have been
mixed together and consolidated into one breccia ; a change soon
effected by the percolation of water charged with carbonate of
lime. It is not on such evidence that we shall readily be in-
duced to admit either the high antiquity of the human race, or
the recent date of certain lost species of quadrupeds.

CHAPTER XIV.

Imbedding of organic remains in alluvium and the ruins caused by landslips —
Effects of sudden inundations — Of landslips — Terrestrial animals most abun-
dantly preserved in alluvium and landslips, where earthquakes prevail —
Erroneous theories which may arise from overlooking this circumstance — On
the remains of works of art included in alluvial deposits — Imbedding of organic
bodies and human remains in blown sand — Temple of Ipsambul on the Nile — ■
Dried carcasses of animals buried in the sands of the African deserts — Towns
overwhelmed by sand-floods in England and France — Imbedding of organic
bodies and works of art in volcanic formations on the land — Cities and their
inhabitants buried by showers of ejected matter — by lava— In tuffs or mud
composed of volcanic sand and ashes.

In continuing our investigation of the manner in which the
animal and vegetable creation leave permanent marks of their
existence on the emerged lands, we have next to examine,

The imbedding of organic remains in alluvium, and the ruins

caused by landslips.

We restrict the term alluvium to such transported matter
as has been thrown down, whether by rivers, floods, or other
causes, upon land not permanently submerged beneath the
waters of lakes or seas.

The alluvium of the bed of a river does not often contain any
animal or vegetable remains, for the whole mass is so continu-
ally shifting its place, and the attrition of the various parts is
so great, that even the hardest rocks contained in it are, at
length, ground down to powder. But when sand, mud, and
rubbish, are suddenly swept by a flood, and then Jet fall upon
the land, such an alluvium may envelop trees or the remains
of animals, which may, in this manner, be permanently
preserved.

The sudden descent of a body of water which had been
discharged by a small artificial drain from a lake in Vermont,
in the United States, in 1810, covered a wide valley with the
spoils of the land washed down from the higher country.

Ch. XIV.]

VILLAGES

BURIED BY LANDSLIPS.

229

Deep accumulations of mud and sand were spread far and
wide, and, in some places, deposits of timber were heaped up,
from twenty to eighty feet in height*.

Analogous results happen, from time to time, when the
course of a river has been obstructed by landslips, volcanic
ejections, masses of ice, or other impediments, and when the
waters of temporary lakes so caused burst through the barrier.
Besides these indirect effects, the landslip, by suddenly precipi-
tating large masses of rock and soil into a valley, overwhelms
a multitude of animals, and sometimes buries permanently
whole villages, with their inhabitants and large herds of cattle.
Thus three villages, with their entire population, were covered,
when the mountain of Piz fell in 1772, in the district of Tre-
viso, in the state of Venice f ; and part of Mount Grenier,
south of Chambery, in Savoy, which fell- down in the year
1248, buried five parishes, including the town and church of
St. Andre, the ruins occupying an extent of about nine square
miles J.

The number of lives lost by the slide of the Rossberg, in
Switzerland, in 1806, was estimated at more than eight hun-
dred, a great number of the bodies being buried under mud
and rock, at great depths, as well as several villages and scat-
tered houses. In the same country, several hundred cottages,
with eighteen of their inhabitants and a great number of cows,
goats, and sheep, were victims to the sudden fall of a bed of
stones, thirty yards deep, which descended from the summits
of the Diablerets. In the year 1618, a portion of Mount
Conto fell, in the county of Chiavenna in Switzerland, and
buried the town of Pleurs with all its inhabitants, to the num-
ber of two thousand four hundred and thirty.

It is unnecessary to multiply examples of similar local catas-
trophes, which, however numerous they may nave been in the
mountainous parts of Europe, within the historical period,
have been, nevertheless, of rare occurrence in comparison to

* Ed. New Phil. Joum., No. III. } 146. f Malte-Brun's Geog., vol. I, 435.
| Bakewell, Travels hi the Tareutaise, vol. i., p. 201.

230 PRESERVATION OF ORGANIC REMAINS [Cli. XIV.

the events of the same kind which take place in regions con-
vulsed by earthquakes. It is then that all the causes whereby
terrestrial animals may be buried in superficial alluvium are
in full activity ; in proof of which, we need only refer the
reader to our description, in the former volume, of the effects
of great subterranean movements in disturbing the drainage of
a country and altering its levels. When the shocks are vio-
lent, enormous masses of rock and earth, even in compara-
tively low and level countries, are detached from the sides of
valleys and cast down into the river-courses. The slides are
so rapid and unexpected, that they often overwhelm, in the
day-time, every living thing upon the plain ; and when they
happen in the night, escape is impossible. Although the
streams are often only partially dammed up by the ruins
thrown into their channel, the waters, nevertheless, collect in
sufficient quantity to form torrents of mud, which, as we have
seen in Calabria, sometimes bear along uprooted trees, and
overwhelm animals until, wherever they cease to move, the
mass shrinks on drying, and becomes hard and compact *.

Many geologists who seem desirous of ascribing as little
power as possible to the aqueous causes now acting, are in the
habit of overlooking the effects which the force of running
water can produce, when combined with the movements of
ordinary earthquakes. In a country like Great Britain, where
the height of mountain-chains is not considerable, and where
the shocks of earthquakes are rare and extremely feeble,
scarcely any remains of terrestrial animals or plants are buried
in alluvial deposits, in such a manner as to lead us to expect
that they will be preserved for indefinite periods. Some
skeletons, it is true, are occasionally imbedded, as, for example,
in the mud and sand produced by the floods in Scotland, in
1829, in which the dead and mutilated bodies of hares,
rabbits, moles, mice, partridges, and even the bodies of men,
were found drifted and partially buried f. But if the levels

* Vol. I, pp. 427 and 428.
f SirT. D. Lauder, Bart-, on the great floods in Morayshire, August, 1829, p. 177.

Ch.XIV.] IN ALLUVIUMS AND LANDSLIPS. 231

of a country remain unchanged, one flood usually effaces the
memorials left by another, and there is rarely a sufficient depth
of undisturbed transported matter in any one spot, to preserve
the organic remains permanently from destruction.

The catastrophes, on the other hand, which arise from re-
peated earthquakes, cause not only the death of many animals,
but their frequent inhumation in alluvium, so placed as to
escape degradation for a succession of ages. When a valley
has been half choked up with mud, sand, and gravel, or when
numerous slides from the boundary hills have encumbered it
with ruin, a river takes a new direction, finding, perhaps, its
way through a new-formed fissure. From that moment the
transported matter is no longer exposed to be undermined and
removed by the action of running water.

Portions, also, of plains loaded with alluvial accumulations
by transient floods, may be gradually upraised by earthquakes ;
and, if any organic remains have been imbedded in the trans-
ported materials, they will, after such elevation, remain undis-
turbed, and beyond the reach of the erosive power of streams.
Every fissure, every hollow caused by the sinking in of land,
becomes a receptacle of organic and inorganic substances,
hurried along by transient floods, in districts where the drain-
age is repeatedly deranged by subterranean movements.

We have seen that the ravines which opened in Calabria, in
1783, were very numerous, varying in depth from fifty to two
hundred feet * ; and that animals were sometimes engulphed
during the shocks. We may assume that many others fell in
during the three years that the earthquakes continued, and that
similar casualties happen in the intervals between convulsions.
Every inundation, therefore, caused by heavy rains, every
torrent that might chance to be in the line of any of these
chasms, would pour in a quantity of mud, sand, and rolled
pebbles, together with fragments of the adjacent rocks, and
under these the animal remains might lie inhumed for ages.

Where houses with their inhabitants have been swallowed

* Vol. i., p. 421.

232

PRESERVATION OF ORGANIC REMAINS

[Ch. XIV.

up in fissures, there appears to have been usually a sliding in
of all the loose matter which lay upon the surface, so that, in
such rents, we might look for rolled pebbles, mud, sand, angu-
lar fragments of rocks, ruins of buildings, and skeletons of men
and animals, at the depth often of several hundreds of feet.
It is obvious that a suite of subterranean caverns, communi-
cating with such fissures, might become wholly, or partially,
filled with these various materials confusedly mixed together.

During the great earthquake of 1693, in Sicily, several
thousand people were at once entombed in the ruins of caverns
in limestone, at Sortino Vecchio ; and, at the same time, a large
stream, which had issued, for ages from one of the grottos
below that town, changed suddenly its subterranean course,
and came out from the mouth of a cave lower down the valley,
where no water had previously flowed. To this new point the
ancient mills were transferred.

When the courses of engulphed rivers are thus liable to
change, from time to time, by alterations in the levels of a
country, and by the rending and shattering of mountain masses,
we must suppose that the dens of wild beasts will sometimes
be inundated by subterranean floods, and their carcasses buried
under heaps of alluvium. The bones, moreover, of indivi-
duals which have died in the recesses of caves, or of animals
which have been carried in for prey, may be drifted along and
mixed up with mud, sand, and fragments of rock, so as to
form osseous breccias.

Nor should we omit to mention the havoc committed on low
coasts, during earthquakes, by waves of the sea which roll in
upon the land, bearing everything before them, for many
miles into the interior throwing down upon the surface great
heaps of sand and rock, by which the remains of drowned
animals may be overwhelmed. Many of the storms, termed
hurricanes, have evidently been connected with submarine
earthquakes, as is shown by the atmospheric phenomena attend-
ant on them, and by the sounds heard in the ground, and the
odours emitted. Such were the circumstances which accom-

Ch. XIV.]

IN ALLUVIUMS AND LANDSLIPS.

233

parried the swell of the sea in Jamaica, in 1780, when a great
wave desolated the western coast, and bursting upon Savanna
la Mar, swept away the whole town in an instant, so that not
a vestige of man, beast, or habitation, was seen upon the
surface # .

Now let us suppose that in a tract of land constantly inha-
bited by terrestrial quadrupeds, the species are thrice changed
under the gradual influence of causes before considered in this
volume., and that, during the first and last of these zoological
epochs, the district remains entirely free from earthquakes, but
is violently convulsed by them during the intermediate era, —
we should expect, for reasons above considered, that the fossil
remains of quadrupeds, buried in alluvium, would be confined
to one pei'iod only, viz., that of the subterranean movements.
If the series of shocks should happen not to have occupied the
whole of the second epoch, but only a small portion of it, there
might be no indication whatever, in the fossil relics, of a pas-
sage from one state of the organic world to another. The
transition would appear abrupt; and they who, for the sake of
economizing past time, do not hesitate to magnify the energies
of natural agents in by-gone ages, might then imagine one
paroxysmal earthquake to have caused all the fissures, caverns,
and depressions, and one accompanying deluge to have filled
the whole with alluvial matter, annihilating, at the same time,
the race of quadrupeds of which the bones remain interred.

But although we conceive that, in a country entirely free
from subterranean movements, a long succession of ages might
pass away without any permanent monuments being left in
alluvium of the terrestrial animals which have lived upon the
surface, yet it appears scarcely possible that man, if he has
made considerable progress in civilization, should fail to leave
some lasting signs of the works of his hands, to testify his
former existence. We are informed by M. Boblaye, that in
the Morea, the formation termed ceramique, consisting of pot-
tery, tiles, and bricks, intermixed with various works of art,

* Edwards, Hist, of West Indies, vol. i., p. 235, Ed. 1801.

234

PRESERVATION OF ORGANIC REMAINS

[Ch. XIV.

enters so largely into the alluvium and vegetable soil upon the
plains of Greece, and into hard and crystalline breccias which
have been formed at the foot of declivities, that it constitutes a
real stratum which might, in the absence of zoological cha-
racters, serve to mark our epoch in a most indestructible
manner *.

Imbedding of Organic Bodies and Human Remains in

Blown Sand.

The drifting of sand is the next cause which we may consider
among those capable of preserving the remains of the inha-
bitants of the land during its period of emersion. We have
already alluded to the African deserts, as the most remarkable
example of desolation produced by this cause. Innumerable
towns and cities have been buried to the westward of the Nile,
between the temple of Jupiter Amnion and Nubia ; and it is
scarcely possible to conceive a mode whereby interment could
take place under circumstances more favourable to the con-
servation of monuments for indefinite periods. The sand
which surrounded and filled the great temple of Ipsambul,
first discovered by Burckhardt, and afterwards partially un-
covered by Belzoni and Beechey, was so fine as to resemble a
fluid when put in motion. Neither the features of the colossal
figures, nor the colour of the stucco with which some were co-
vered, nor the paintings on the walls, had received any injury
from being enveloped for ages in this dry impalpable dust f.

At some future period, perhaps, when the pyramids shall
have perished, the action of the sea, or an earthquake, may lay
open to the day some of these buried temples. Or we may
suppose the desert to remain undisturbed, and changes in
the surrounding sea and land to modify the climate and the
direction of the prevailing winds, so that these may then waft
away the Lybian sands as gradually as they once brought them
to those regions. Thus many a town and temple of higher
antiquity than Thebes or Memphis might reappear in their

* Ann. des Sci. Nat., tome xxii., p. 117. Feb. 1831.
f Stratton, Ed. Phil, Journ, No. V., p. 62.

Ch.XIV.] AND WORKS OF ART IN BLOWN SAND. 235

original integrity, and a part of the gloom which overhangs
the history of earlier nations might be dispelled.

Whole caravans are said to have been overwhelmed by
the Lybian sands ; and Burckhardt informs us that " after
passing the Akaba, near the head of the Red Sea, the bones
of dead camels are the only guides of the pilgrim through the
wastes of sand." " We did not see," says Captain Lyon,
speaking of a plain near the Soudah mountains, in Northern
Africa, " the least appearance of vegetation ; but observed
many skeletons of animals, which had died of fatigue on the
desert, and occasionally the grave of some human being. All
these bodies were so dried by the heat of the sun, that putre-
faction appears not to have taken place after death. In
recently-expired animals I could not perceive the slightest
offensive smell ; and in those long dead the skin with the hair
on it remained unbroken and perfect, although so brittle as to
break with a slight blow. The sand-winds never cause these
carcasses to change their places, for in a short time a slight
mound is formed round them, and they become stationary

The burying of several towns and villages in England and
France by blown sand is on record ; thus for example in Suf-
folk, in the year 1688, part of Downham was overwhelmed by
sands which had broken loose about one hundred years before,
from a warren five miles to the south-west. This sand had, in
the course of a century, travelled five miles, and covered more
than a thousand acres of land f.

The ruins of buildings have been found entire in the drift-
sand of Cornwall, as we before mentioned, as also land-shells.
One of the latter is said to belong to a species which is un-
known at present in this country |, Near St. Pol de Leon, in
Brittany, a whole village was completely buried beneath drift-
sand, so that nothing was seen but the spire of the church §.

* Travels in Northern Africa in the years 1818, 1819, and 1820, p. 83.
f Phil. Trans, vol. ii., p. 722.
I Vol. i., p. 301.

§ Mem. de l'Acad. des Sci. de Paris, 1772.— Malte-Brun's Geog. vol. i. ; p. 425. 1

236 IMBEDDING OF ORGANIC AND OTHER REMAINS [Ch. XIV.

Imbedding of Organic Bodies and Works of Art in Volcanic
Formations on the Land.

We have in some degree anticipated the subject of this section
in a former volume, when speaking of the buried cities around
Naples, and those on the flanks of Etna *. From the facts
referred to by us, it appears that the preservation of human
remains and works of art has been frequently due to the
descent of floods caused by the copious rains which usually
accompany eruptions. These aqueous lavas, as they are called
in Campania, flow with great rapidity, and in 1822 surprised
and suffocated, as we have stated, seven persons in the villages
of St. Sebastian and Massa, on the flanks of Vesuvius.

In the tuffs, moreover, or solidified mud, deposited by these
aqueous lavas, impressions of leaves and of trees have been
observed. Some of those formed after the eruption of Vesu-
vius in 1822, are now preserved in the museum at Naples.

Lava itself may become indirectly the means of preserving
terrestrial remains, by overflowing beds of ashes, pumice, and
ejected matter, which may have been showered down upon
animals and plants, or upon human remains. Few sub-
stances are better non-conductors of heat than volcanic dust
and scoria?, so that a bed of such materials is rarely melted
by a superimposed lava-current. After consolidation, the lava
affords secure protection to the lighter and more immoveable
mass below, wherein the organic relics may be enveloped.
The Herculanean tuffs containing the rolls of papyrus, of
which the characters are still legible., have, as we before re-
marked, been for ages covered by lava.

Another mode whereby lava may tend to the conservation
of imbedded remains, at least of works of human art, is by
overflowing them when not intensely heated, in which case
they often suffer little or no injury.

Thus when the Etnean lava-current of 1669 covered fourteen
towns and villages, and part of the city of Catania, it did not

* Vol. i., pp. 349 and 365.

Ch. XIV.]

IN VOLCANIC FORMATIONS ON THE LAND.

237

melt down a great number of statues and other articles in the
vaults of Catania ; and at the depth of thirty-five feet in the
same current, on the site of Mompiliere, one of the buried
towns, the bell of a church and some statues were found un-
injured *.

We remarked in a former volume, that in many countries
which have been peopled from remote ages by civilized nations,
and have been at the same time the theatres of volcanic action,
there must be innumerable monuments of the highest value to
the historian, which continue unobserved " because they have
not been searched for." But we omitted to describe in detail
a splendid example of several buried cities in Central India,
which might probably be made to yield a richer harvest to the
antiquary than Pompeii and Herculaneum f . The city of
Oujein (or Oojain) was, about fifty years before the Christian
aera, the seat of empire, of art, and of learning ; but in the time
of the Rajah Vicramaditya, it was overwhelmed, together, as
tradition reports, with more than eighty other large towns in
the provinces of Malwa and Bagur, " by a shower of earth."
The city which now bears the name is situated a mile to the
southward of the ancient town. On digging on the spot where
the latter is supposed to have stood, to the depth of fifteen or
eighteen feet, there are frequently discovered, says Mr. Hunter,
entire brick walls, pillars of stone, and pieces of wood of an
extraordinary hardness, besides utensils of various kinds, and
ancient coins. Many coins are also found in the channels cut
by the periodical rains, or in the beds of torrents into which
they have been washed. " During our stay at Oujein, a large
quantity of wheat was found by a man digging for bricks. It
was, as might have been expected, almost entirely consumed,
and in a state resembling charcoal. In a ravine cut by the
rains, from which several stone pillars had been dug, I saw a
space from twelve to fifteen feet long and seven or eight high,
composed of earthen vessels, broken and closely compacted
together. It was conjectured, with great appearance of proba-
bility, to have been a potter's kiln. Between this place and
* Vol. i., p. 366. f Ibid., p. 407.

238

BURIED CITIES IN CENTRAL INDIA.

[Ch. XIV.

the new town is a hollow, in which; tradition says, the river
Sipparah formerly ran. It changed its course at the time the
city was buried, and now runs to the westward *." The soil
which covers Oujein is described as " being of an ash-grey
colour, with minute specks of black sand-f*."

That the et shower of earth " which is reported to have
" fallen from heaven," was produced by a volcanic eruption,
we cannot doubt, although no information has been obtained
respecting the site of the vent ; and the nearest volcano of
which we read, is that which was in eruption during the dutch
earthquake in 1819, at the distance of about thirty miles from
Bhooi, the capital of dutch, and at least three hundred geogra-
phical miles from Oujein.

daptain F. Dangerfield., who accompanied Sir John Mal-
colm in his late expedition into dentral India, states that the
river Nerbuddah, in Malwa, has its channel excavated through
columnar basalt, on which rest beds of marl impregnated with
salt. The upper of these beds is of a light colour, and from
thirty to forty feet thick, and rests horizontally on the lower
bed, which is of a reddish colour. Both appear from the
description to be tuffs composed of the materials of volcanic
ejections, and forming a covering from sixty to seventy feet
deep overlying the basalt, which seems to resemble some of the
currents of prismatic lava in Auvergne and the Vivarais. Near
the middle of this tufaceous mass, and therefore at the depth
of thirty feet or more from the surface, just where the two
beds of tuff meet, daptain Dangerfield was shown, near the
city of Mhysir, buried bricks and large earthen vessels, said to
have belonged to the ancient city of Mhysir, destroyed by the
catastrophe of Oujein %.

* Narrative of a Journey from Agra to Oujein, Asiatic Researches, vol. vi. p. 36.
f Asiatic Journal, vol. ix. p. 35.
% Sir J. Malcolm's Cent. Ind.— Geol. of Malwa, by Captain F. Dangerfield,
App. No. ii. pp. 324, 325.

CHAPTER XV.

Imbedding of organic remains in subaqueous deposits— Division of the subject —
Phenomena relating to terrestrial animals and plants first considered — Wood
sunk to a great depth in the sea instantly impregnated with salt-water —
Experiments of Scoresby — Drift timber carried by the Mackenzie into Slave
Lake and into the sea — Cause of the abundance of drift timber in this
river — Floating trees in the Mississippi — In the Gulf stream — Immense
quantity thrown upon the coast of Iceland, Spitzbergen, and Labrador — Im-
bedding of the remains of insects — of the remains of reptiles — Why the bones
of birds are so rare in subaqueous deposits — Imbedding of terrestrial quadru-
peds — Effects of a flood in the Solway Firth — Wild horses annually drowned
in the savannahs of South America— Skeletons in recent shell marl — Drifting
of mammiferous and other remains by tides and currents.

We have treated hitherto of the imbedding of organic remains
in deposits formed upon the emerged land, and we shall next
consider the including of the same in deposits formed under
water.

It will be convenient to divide this branch of our subject
into three parts ; considering first, the various modes whereby
the relics of terrestrial species may be buried in subaqueous
formations ; secondly, the modes whereby the animals and
plants inhabiting fresh-water may be so entombed ; thirdly,
the manner in which marine species may become preserved in
new strata.

The phenomena which we are now about to notice demand
a fuller share of -attention than those previously examined,
since the deposits which originate upon the dry land are
insignificant in thickness, superficial extent, and durability,
when contrasted with those of subaqueous origin. At the
same time, the study of the latter is beset with greater diffi-
culties, for we are here concerned with the results of processes
much more removed from the sphere of ordinary observation.
There is^ indeed, no circumstance, as we before remarked*,

* Vol. i., p. 81.

240 IMBEDDING OF TERRESTRIAL PLANTS. [Ch. XV.

which more seriously impedes the acquisition of just views in
the etiology of our science^ than an habitual disregard of the
important fact, that the reproductive effects of the principal
agents of change are confined to another element, — to that
larger portion of the habitable globe, from which, by our very
organization, we are almost entirely excluded.

Imbedding of Terrestrial Plants.

When a tree falls into a river from the undermining of the
banks, or from being washed in by a torrent or flood, it floats
on the surface, not because the woody portion is specifically
lighter than water, but because it is full of pores containing
air. When soaked for a considerable time, the water makes
its way into these pores, and the wood becomes water-logged
and sinks. The time required for this process varies differ-
ently in different woods, but several kinds may be drifted to
great distances, sometimes across the ocean, before they lose
their buoyancy.

If wood be sunk to vast depths in the sea, it may be
impregnated with water suddenly. Captain Scoresby informs
us, in his Account of the Arctic Regions *, that on one occa-
sion a whale, on being harpooned, ran out all the lines in the
boat, which it then dragged under water, the men having just
time to escape to a piece of ice. When the fish returned to
the surface *« to blow," it was struck a second time, and soon
afterwards killed. The moment it expired it began to sink, —
an unusual circumstance, which was found to be caused by the
weight of the sunken boat which still remained attached to it.
By means of harpoons and ropes the fish was prevented from
sinking until it was released from the weight by connecting a
rope to the lines of the attached boat, which was no sooner
done than the fish rose again to the surface. The sunken
boat was then hauled up with great labour, for so heavy was
it, that although before the accident it would have been
buoyant when full of water, yet it now required a boat at each

* VoUi.p. 191.

Ch. XV.] IMBEDDING OF TERRESTRIAL PLANTS.

241

end to keep it from sinking. '* When it was hoisted into the
ship, the paint came off the wood in large sheets ; and the
planks, which were of wainscot, were as completely soaked in
every pore as if they had lain at the bottom of the sea since
the Flood ! A wooden apparatus that accompanied the boat in
its progress through the deep, consisting chiefly of a piece of
thick deal, about fifteen inches square, happened to fall over-
board, and, though it originally consisted of the lightest fir,
sank in the water like a stone. The boat was rendered use-
less ; even the wood of which it was built, on being offered to
the cook for fuel, was tried and rejected as incombustible *."

Captain Scoresby found that by sinking pieces of fir, elm,
ash, &c, to the depth of four thousand and sometimes six
thousand feet, they became impregnated with sea-water, and
when drawn up again, after immersion for an hour, would
no longer float. The effect of this impregnation was to in-
crease the dimensions as well as the specific gravity of the
wood, every solid inch having increased one-twentieth in size
and twenty-one twenty-fifths in weight f.

When timber is drifted down by a river, it is often arrested
by lakes, and becoming water-logged it may sink and be im-
bedded in lacustrine strata, if any be there forming : some-
times a portion floats on till it reaches the sea. In the course
of the Mackenzie Eiver we have an example of vast accumu-
lations of vegetable matter now in progress under both these
circumstances.

In Slave Lake in particular, which vies in dimensions with
some of the great fresh- water seas of Canada, the quantity of
drift- timber brought down annually is enormous. "•' As the
trees," says Dr. Richardson, (t retain their roots, which are
often loaded with earth and stones, they readily sink, espe-
cially when water-soaked, and, accumulating in the eddies,
form shoals, which ultimately augment into islands. A thicket
of small willows covers the new-formed island as soon as it
appears above water, and their fibrous roots serve to bind the

* Account of the Arctic Regions, vol. ii. p. 193. f lb. "p. 202.

VOL. II. R

£4$ DRIFT TIMBER OF THE MACKENZIE. [Ch. XV.

whole firmly together. Sections of these islands are annually
made by the river, assisted by the frost; and it is interesting
to study the diversity of appearances they present according
to their different ages. The trunks of the trees gradually
decay until they are converted into a blackish brown sub-
stance resembling peat, but which still retains more or less of
the fibrous structure of the wood ; and layers of this often
alternate with layers of clay and sand, the whole being pene-
trated, to the depth of four or five yards or more, by the long
fibrous roots of the willows. A deposition of this kind, with
the aid of a little infiltration of bituminous matter, would pro-
duce an excellent imitation of coal, with vegetable impressions
of the willow roots. What appeared most remarkable was the
horizontal slaty structure that the older alluvial banks pre-
sented, or the regular curve that the strata assumed from
unequal subsidence.

" It was in the rivers only that we could observe sections of
these deposits, but the same operation goes on on a much more
magnificent scale in the lakes. A shoal of many miles in ex-
tent is formed on the south side of Athabasca Lake, by the
drift-timber and vegetable debris brought down by the Elk
River ; and the Slave Lake itself must in process of time be
filled up by the matters daily conveyed into it from Slave-
River. Vast quantities of drift timber are buried under the
sand at the mouth of the river, and enormous piles of it are
accumulated on the shores of every part of the lake *."

The banks of the Mackenzie display almost everywhere
horizontal beds of wood coal, alternating with bituminous clay,
gravel, sand, and friable sandstone ; sections, in short, of such
deposits as are now evidently forming at the bottom of the
lakes which it traverses.

Notwithstanding the vast forests intercepted by the lakes, a
still greater mass of drift-wood is found where the Mackenzie
reaches the sea, in a latitude where no wood grows at present
except a few stunted willows. At the mouths of the river the

2 Dr. Richardson's Geognost. Obs. on Capt. Franklin's Polar Expedition.

Ch. XV.] IMBEDDING OF TERRESTKIAL PLANTS.

243

alluvial matter has formed a barrier of islands and shoals,
where we may expect a great formation of coal at some distant
period.

The abundance of floating timber on the Mackenzie is
owing, as I am informed by Dr. Richardson, to the peculiar
direction and to the length of the course of this river, which
runs from south to north, so that the sources of the stream lie
in much warmer latitudes than its mouths. In the country,
therefore, where the former are situated, the frost breaks up at
an earlier season, while yet the waters in the lower part of its
course are ice-bound. Hence the current of water, rushing
down northward, reaches a point where the thaw has not
begun, and finding the channel of the river blocked up with
ice, it overflows the banks, sweeping through forests of pines,
and carrying away thousands of uprooted trees.

We have already observed* that the navigation of the
Mississippi is much impeded by trunks of trees half sunk in
the river. On reaching the Gulf of Mexico many of them
subside and are imbedded in the new strata which form
the delta, but many of them float on and enter the Gulf-
stream. ce Tropical plants, (says M. Constant Prevost,) are taken
up by this great current, and carried in a northerly direction,
till they reach the shores of Iceland and Spitzbergen uninjured.
A great portion of them are doubtless arrested on their
passage, and, probably, always in the same inlets, or the same
spots on the bottom of the ocean ; in fact, wherever an eddy or
calm determines their distribution, which, in this single ex-
ample, extends over a space comprehended between the equator
and the eightieth degree of latitude — an immense space, six
times more considerable than that occupied by all Europe,
and thirty times larger than France. The drifting of various
substances, though regular, is not continual ; it takes place by
intermittance after great inundations of rivers, and in the in-
tervals the waters may only carry sand or mud, or each of
these alternately, to the same localities f."

* Vol. i. p. 245. f Mem. de la Soc. d'Hist. Nat. de Paris, vol. iv. p. 84,

R 2

244

DltTFT-WOOD OF THE NORTH SEA.

[Ch. XV.

The ancient forests of Iceland, as Malte-Brun observes, have
oeen improvidently exhausted ; but, although the Icelander can
obtain, no timber from the land, he is supplied with it abun-
dantly by the ocean. An immense quantity of thick trunks
of pines, firs, and other trees, are thrown upon the northern
coast of the island, especially upon North Cape and Cape
Langaness, and are then carried by the waves along these two
promontories to other parts of the coast, so as to afford suf-
ficiency of wood for fuel and for constructing boats. Timber
is also carried to the shores of Labrador and Greenland ; and
Crantz assures us that the masses of floating wood thrown by
the waves upon the island of John de Mayen often equal
the whole of that island in extent *.

In a similar manner the bays of Spitzbergen are filled with
drift-wood, which accumulates also upon those parts of the
coast of Siberia that are exposed to the east, consisting of
larch trees, pines, Siberian cedars, firs, and Fernambucco and
Campeachy woods. These trunks appear to have been swept
away by the great rivers of Asia and America. Some of them
are brought from the Gulf of Mexico, by the Bahama stream,
while others are hurried forward by the current which, to the
north of Siberia, constantly sets in from east to west. Some
of these trees have been deprived of their bark by friction,
but are in such a state of preservation as to form excellent
building timber f. Parts of the branches and almost all the
roots remain fixed to the pines which have been drifted into
the North Sea, into latitudes too cold for the growth of such
timber, but the trunks are usually barked.

The leaves and lighter parts of plants are seldom carried
out to sea, in any part of the globe, except during tropical
hurricanes among islands, and during the agitations of the
atmosphere which sometimes accompany earthquakes and vol-
canic eruptions]:.

* Malte-Brun, Geog. vol. v. part i. p. 112. — Crantz, Hist, of Greenland, tome i.
pp. 50—54.

f Olafsen, Voyage to Iceland, tome i. Malte-Brun's Geog. vol. v. part i. p. 112.
X De la Beche, Geol. Manual, p. 477.

Ch. XV.]

IMBEDDING OF THE REMAINS OF INSECTS.

245

It will appear from these observations, that although the
remains of terrestrial vegetation, borne down by aqueous causes
from the land, are chiefly deposited at the bottom of lakes or
at the mouths of rivers, yet a considerable quantity is drifted
about in all directions by currents, and may become imbedded
in any marine formation, or may sink down, when water-
logged, to the bottom of unfathomable abysses, and there
accumulate without intermixture of other substances.

It may be asked whether we have any data for inferring that
the remains of a considerable proportion of the existing species
of plants will be permanently preserved, so as to be hereafter
recognizable, supposing the strata now in progress to be at
some future period upraised? To this inquiry we may reply
that there are no reasons for expecting that more than a small
number of the plants now flourishing in the globe will become
fossilized, since the entire habitations of a great number of
them are remote from lakes and seas, and even where they
grow near to large bodies of water, the circumstances are quite
accidental and partial which favour the imbedding and con-
servation of vegetable remains. Those naturalists, therefore,
who infer that the ancient flora of the globe was, at certain
periods, less varied than now, merely because they have as
yet discovered only a few hundred fossil species of a particular
epoch, while they can enumerate more than fifty thousand living
ones, are reasoning on a false basis, and their standard of com-
parison is not the same in the two cases.

Imbedding of the Remains of Insects.

I have observed the elytra and other parts of beetles in a band
of fissile clay, separating two beds of recent shell-marl, in the
Loch of Kinnordy. Amongst these, Mr. Curtis recognized
Elater lineatus and Atopa cervina, species still living in Scot-
land. These, as well as other remains which accompanied them;,
appear to belong to terrestrial, not aquatic species, and must
have been carried down in muddy water during an inundation.

246 IMBEDDING OF REMAINS OF REPTILES AND BIRDS. [Ch. XV.

In the lacustrine peat of the same locality, the elytra of beetles
are not uncommon ; but in the deposits of drained lakes gene-
rally, and in the silt of our estuaries, the relics of this class of
the animal kingdom are extremely rare. In the blue clay of
very modern origin of Lewes Levels, Mr. Mantell has found
the Indusia, or cases of the larvae of Phryganea, in abundance,
with minute shells belonging to the genera Planorbis, Lim-
nea, &c, adhering to them %

When speaking of the migrations of insects, we pointed
out that an immense number are floated into lakes and seas by
rivers, or blown by winds far from the land ; but they are so
buoyant that we can only suppose them, under very peculiar
circumstances, to sink to the bottom before they are either
devoured by insectivorous animals or are decomposed.

Remains of Reptiles.

As the bodies of several crocodiles were found in the mud
brought down to the sea by the river inundation which
attended an earthquake in Java in the year 1699, we. may
imagine that extraordinary floods of mud may stifle many
individuals of the shoals of alligators and other reptiles which
frequent lakes and the deltas of rivers in tropical climates.
Thousands of frogs were found leaping about among the
wreck carried into the sea by the late inundations in Moray-
shire "f ; and it is evident that whenever a sea-cliff is under-
mined, or land is swept by other violent causes into the sea,
land reptiles may be carried in.

Remains of Birds.

We might have anticipated that the imbedding of the remains
of birds in new strata would be of very rare occurrence, for
their powers of flight insure them against perishing by nu-
merous casualties to which quadrupeds are exposed during

* Trans. Geol. Soc. vol. iii. part i. p. 201, Second Series,
f Sir T. D. Lauder's Account, Second Ed., p. 312,

Ch.XV.] IMBEDDING OF TERRESTRIAL QUADRUPEDS. 247

floods ; and if they chance to be drowned, or to die when
swimming on the water, it will scarcely ever happen that they
will be submerged so as to become preserved in sedimentary
deposits. For in consequence of the hollow tubular structure
of their bones and the quantity of their feathers, they are
extremely light in proportion to their volume, so that when
first killed they do not sink to the bottom like quadrupeds,
but float on the surface until the carcass either rots away
or is devoured by predaceous animals. To these causes we
may ascribe the absence of any vestige of the bones of birds
in the recent marl formations of Scotland : although these
lakes, until the moment when they were artificially drained,
were frequented by a great abundance of water- fowl.

Imbedding of Terrestrial Quadrupeds.

River inundations recur in most climates at very irregular
intervals, and expend their fury on those rich alluvial plains
where herds of herbivorous quadrupeds congregate together.
These animals are often surprised, and being unable to stem the
current, are hurried along until they are drowned, when they
sink immediately to the bottom. Here their bodies are drifted
along, together with sediment, into lakes or seas, and may then
be covered by a mass of mud, sand, and pebbles, thrown down
upon them. If there be no sediment superimposed, the gases
generated by putrefaction usually cause the bodies to rise
again to the surface about the ninth, or at most the fourteenth
day. The pressure of a thin covering would not be sufficient
to retain them at the bottom, for we see the putrid carcasses
of dogs and cats, even in rivers, floating with considerable
weights attached to them, and they would be still more buoyant
in sea-water.

In cases where the body is so buried in drift-sand, or mud
accumulated upon it, as never to rise again, the skeleton
may be preserved entire ; but if it comes again to the surface
while in the process of putrefaction, the bones commonly fall

248 IMBEDDING OF TERRESTRIAL QUADRUPEDS [Ch. XV.

piecemeal from the floating carcass, and may in that case be-
come scattered at random over the bottom of a lake, estuary,
or sea, so that a jaw may afterwards be found in one place, a
rib in another, a humerus in a third — all included, perhaps,
in a matrix of fine materials, and where there may be evidence
of very slight transporting power in the current, or even of
none, but simply of some chemical precipitate.

A large number of the bodies of drowned animals, if they
float into the sea or a lake, especially in hot climates, are in-
stantly devoured by sharks, alligators, and other carnivorous
beasts, which may have power to digest even the bones. But
during extraordinary floods, when the greatest number of land
animals are destroyed, the waters are commonly so turbid,
especially at the bottom of the channel, that even aquatic
species are compelled to escape into some retreat where there is
clearer water, lest they should be stifled. For this reason, as
well as the rapidity of sedimentary deposition at such seasons,
the probability of some carcasses becoming permanently im-
bedded is considerable.

One of the most memorable floods of modern date, in our
island, is that which visited part of the southern borders of
Scotland, on the 24th of January, 1794, and which spread
particular devastation over the country adjoining the Solway
Frith.

We learn from the account of Captain Napier, that the
heavy rains had swollen every stream which entered the Frith
of Solway, so that the inundation not only carried away a great
number of cattle and sheep, but many of the herdsmen and
shepherds, washing down their bodies into the estuary. After
the storm, when the flood subsided, an extraordinary spectacle
was seen on a large sand-bank, called " the beds of Esk/'
where there is a meeting of the tidal waters, and where heavy
bodies are usually left stranded after great floods. On this single
bank were found collected together the bodies of nine black
cattle, three horses, one thousand eight hundred and forty
sheep, forty-five dogs, one hundred and eighty hares, besides

Ch. XV.]

BY RIVEll INUNDATIONS.

249

a great number of smaller animals, and, mingled with the
rest, the corpses of two men and one woman *.

In those more recent floods in Scotland, in August 1829,
whereby a fertile district, six hundred miles in length, became
a scene of dreadful desolation, a vast number of animals and
plants were washed from the land, and found scattered about
after the storm, around the mouths of the principal rivers.
An eye-witness thus describes the scene which presented itself
at the mouth of the Spey, in Morayshire. " For several
miles along the beach, crowds were employed in endeavouring
to save the wood and other wreck with which the heavy rolling
tide was loaded ; whilst the margin of the sea was strewed
with the carcasses of domestic animals, and with millions of
dead hares and rabbits. Thousands of living frogs, also, swept
from the fields, no one can say how far off, were observed
leaping among the wreck

We are informed by Humboldt, that during the periodical
swellings of the large rivers in South America, great numbers
of quadrupeds are annually drowned. Of the wild horses, for
example, which graze in immense troops in the savannahs,
thousands are said to perish when the river Apure is swollen,
before they have time to reach the rising grounds of the
Llanos. The mares, during the season of high water, may be
seen, followed by their colts, swimming about and feeding on
the grass of which the top alone waves above the Avaters. In
this state they are pursued by crocodiles ; and their thighs
frequently bear the prints of the teeth of these carnivorous
reptiles. " Such is the pliability," observes the celebrated
traveller, " of the organization of the animals which man has
subjected to his sway, that horses, cows, and other species of
European origin, lead, for a time, an amphibious life, sur-
rounded by crocodiles, water-serpents, and manatees. When
the rivers return again into their beds, they roam in the savan-

* Treatise on Practical Store Farming, p. 25.
f Sir T. D. Lauder's Account of the Great Floods in Morayshire, August
1829, p. 312 ; Second Ed.

250

SKELETONS IN RECENT SHELL-MARL.

[Ch.XV.

nah, which is then spread over with a fine odoriferous grass,
and enjoy, as in their native climate, the renewed vegetation
of spring

We find it continually stated, by those who describe the
Ganges and Burrampooter, that these rivers carry before them,
during the flood season, not only floats of reeds and timber,
but dead bodies of men, deer, and oxen f.

We have already referred to the effects of a flood which
attended an earthquake in Java in 1699, when the turbid
waters of the Batavian river destroyed all the fish except the
carp ; and when drowned buffaloes, tigers, rhinoceroses, deer,
apes, and other wild beasts, were brought down to the sea-
coast by the current, with several crocodiles which had been
stifled in the mud|.

On the western side of the same island, in the territory of
Goulongong, in the regencies, a more recent volcanic eruption
(1821) was attended by a flood, during which the river Tjetan-
doy bore down hundreds of carcasses of rhinoceroses and
buffaloes, and swept away more than one hundred men and
women from a multitude assembled on its banks to celebrate
a festival. Whether the bodies reached the sea, or were depo-
sited, with drift matter, in some of the large intervening
alluvial plains, we are not informed §.

We might enumerate a great number of local deluges that
have swept through the fertile lands which border on large
rivers, especially in tropical countries, but we should surpass
the limits of this work. We may observe, however, that the
destruction of islands, in rivers, is often attended with great
loss of lives. Thus, when the principal river in Virginia rose,
in 1771j to the height of twenty-five feet above its ordinary
level, it swept entirely away Elk Island, on which were seven

* Humboldt's Pers. Narr., vol. iv., pp. 394—396.
f Malte-Brun, Geog., vol. iii., p. 22. J See ante, vol. i., p. 444.

§ This account I had from Mr. Baumhauer, Director-General of Finances in
Java.

Ch. XV.] REMAINS OF QUADRUPEDS IN MARL LAKES. 251

hundred head of quadrupeds, — horses, oxen, sheep, and
hogs, — and nearly one hundred houses *.

The reader will gather, from what we have said in a former
volume respecting the deposition of sediment by aqueous
causes, that the greater number of the remains of quadrupeds
drifted away by rivers must be intercepted by lakes before
they reach the sea, or buried in fresh-water formations near
the mouths of rivers. If they are carried still farther, the
probabilities are increased of their rising to the surface in a
state of putrefaction, and, in that case, of being there devoured
by aquatic beasts of prey, or of subsiding into some spots
whither no sediment is conveyed, and, consequently, where
every vestige of them will, in the course of time, disappear.

In some instances, the skeletons of quadrupeds are met with
abundantly in recent shell-marls in Scotland, where we cannot
suppose them to have been imbedded by the action of rivers
or floods. They all belong to species which now inhabit, or are
known to have been indigenous in Scotland. The remains of
several hundred skeletons have been procured within the last
century, from five or six small lakes in Forfarshire, where shell-
marl has been worked. Those of the stag (Cervus elaphus)
are most numerous, and if the others be arranged in the order
of their relative abundance, they will follow nearly thus : the
ox, the boar, the horse, the sheep, the dog, the hare, the fox,
the wolf, and the cat. The beaver seems extremely rare,
but it has been found in the shell-marl of Loch Marlie, in
Perthshire, and in the parish of Edrom, in Berwickshire.

In the greater part of these lake deposits there are no signs
of floods, and the expanse of water was originally so confined,
that the smallest of the above-mentioned quadrupeds could
have crossed, by swimming, from one shore to the other.
Deer, and such species as take readily to the water, may often
have been mired in trying to land, where the bottom was soft
and quaggy, and, in their efforts to escape, may have plunged
deeper into the marly bottom. Some individuals, we suspect,

* ScotsJMag., vol. xxxiii.

REMAINS OF QUADRUPEDS IN MARL LAKES.

[Ch. XV.

of different species, have fallen in when crossing the frozen
surface in winter, for nothing can be more treacherous than the
ice when covered with snow, in consequence of the springs,
which are numerous, and which, always retaining an equal
temperature, cause the ice, in certain spots, to be extremely
thin, while, in every other part of the lake, it is strong enough
to bear the heaviest weights.

As the bones of mammalia are often so abundantly pre-
served in peat, and in such lakes as we have just described, the
encroachments of a sea upon a coast may sometimes throw down
the imbedded skeletons, so that they may be carried away by
tides and currents, and entombed in subaqueous formations.
Some of the smaller quadrupeds, also, which burrow in the
ground, as well as reptiles and every species of plant, are liable
to be cast down into the waves by this cause, which must not
be overlooked, although we believe it to be of comparatively
small importance amongst the numerous agents whereby ter-
restrial organic remains may be included in submarine strata.

CHAPTER XVI.

Imbedding of the remains of man and his works in subaqueous strata — Drifting of
bodies to the sea by river-inundations — Destruction of bridges and houses —
Burial of human bodies in the sea — Loss of lives by shipwreck — Circumstances
under which human corpses may be preserved under a great thickness of recent
deposits — Number of wrecked vessels — Durable character of many of their con-
tents — Examples of fossil skeletons of men — Of fossil canoes, ships, and works
of art — Of the chemical changes which certain metallic instruments have
undergone after long submergence — Effects of the subsidence of land in im-
bedding cities and forests in subaqueous strata — Earthquake of Cutch in 1819 —
Submarine forests — Berkley's arguments for the recent date of the creation of
man — Concluding remarks.

We shall now proceed to inquire in what manner the mortal
remains of man and the works of his hands may be perma-
nently preserved in subaqueous strata. Of the many hundred
million human beings which perish in the course of every
century on the land, every vestige is usually destroyed in the
course of a few thousand years, but of the smaller number that
perish in the waters, a considerable proportion must frequently
be entombed, under such circumstances,, that parts of them
may endure throughout entire geological epochs.

We have already seen how the bodies of men, together with
those of the inferior animals, are occasionally washed down
during river-inundations into seas and lakes, of which we shall
now enumerate some additional examples.

Belzoni witnessed a flood on the Nile in September, 1818,
where, although the river only rose three feet and a half above
its ordinary level, several villages, with some hundreds of men,
women, and children, were swept away *. We mentioned in
a former volume that a rise of six feet of water in the Ganges
in 1763, was attended with a much greater loss of lives.

In the year 1771, at the time of the bursting of the Sol-

* Narrative of Discovery in Egypt, &c. London, 1820.

254 IMBEDDING OF THE REMAINS OF MAN [Ch. XVI.

way moss before alluded to, when the inundations in the
north of England appear to have equalled the recent floods in
Morayshire, a great number of houses and their inhabitants
were swept away by the rivers Tyne, Can, Wear, Tees, and.
Greta; and no less than twenty-one bridges were destroyed
in the courses of these rivers. At the village of By well the
flood tore the dead bodies and coffins out of the churchyard,
and bore them away, together with many of the living in-
habitants. During the same tempest an immense number of
cattle, horses, and sheep, were also transported to the sea,
while the whole coast was covered with the wreck of ships.
Four centuries before (in 1338), the same district had been
visited by a similar continuance of heavy rains followed by
disastrous floods, and it is not improbable that these catas-
trophes may recur periodically. As the population increases,
and buildings and bridges are multiplied, we must expect that
the loss of lives and property will rather augment *.

If to the hundreds of human bodies committed to the deep
in the way of ordinary burial, we add those of individuals lost
by shipwreck, we shall find that, in the course of a single year,
a great number of human remains are consigned to the sub-
aqueous regions. We shall hereafter advert to a calculation
by which it appears that more than five hundred British
vessels alone, averaging each a burden of about one hundred
and twenty tons, are wrecked, and sink to the bottom, annu-
ally. Of these the crews for the most part escape, although it
sometimes happens that all perish. In one great naval action
several thousand individuals sometimes share a watery grave.

Many of these corpses are instantly devoured by predaceous
fish, sometimes before they reach the bottom ; still more fre-
quently when they rise again to the surface and float in a state
of putrefaction. Many decompose on the floor of the ocean
where no sediment is thrown down upon them, but if they fall
upon a reef where corals and shells are becoming agglutinated
into a solid rock 5 or subside where the delta of a river is ad-

* Scots Mag., vol. xxxiii. 1771.

Ch. XVI.] AND HIS WOltKS, IN SUBAQUEOUS STRATA. 255

vancing, they may be preserved for an incalculable series of
ages in these deposits.

Often at the distance of a few hundred feet from a coral
reef there are no soundings at the depth of many hundred
fathoms Here if a ship strike and be wrecked, it may soon be
covered by calcareous sand and fragments of coral detached
by the breakers from the summit of a submarine mountain,
and which may roll down to its base. Wrecks are known to
have been common for centuries near certain reefs, so that
canoes, merchant vessels, and ships of war may have sunk and
have been enveloped in these situations in calcareous sand and
breccia. Suppose a volcanic eruption to cover such remains
with ashes and sand, and that over the tufaceous strata
resulting from these ejections, a current of lava is afterwards
poured, the ships and human skeletons might then remain
uninjured beneath the superincumbent rock, like the houses
and works of art in the subterranean cities of Campania.
That cases may have already occurred where human remains
have been thus preserved in a fossil state beneath masses more
than a thousand feet in thickness, is by no means improbable,
for in some volcanic archipelagos a period of thirty or forty
centuries might well suffice for such an accumulation of
matter.

We stated that at the distance of about forty miles from
the base of the delta of the Ganges, there is a circular space
about fifteen miles in diameter where soundings of a thousand
feet sometimes fail to reach the bottom. As during the flood
season the quantity of mud and sand poured by the great
rivers into the Bay of Bengal, is so great that the sea only
recovers its transparency at the distance of sixty miles from
the coast, this depression must be gradually shoaling, espe-
cially as during the monsoons the sea, loaded with mud and
sand, is beaten back in that direction towards the delta. Now
if a ship or human body sink down to the bottom in such a
spot, it is by no means improbable that it may become buried
under a depth of three or four thousand feet of sediment in
the same number of years,

256 IMBEDDING OF THE REMAINS. OF MAN [Ch. XVI.

Even on that part of the floor of the ocean whither no
accession of drift matter is carried, (a part which we believe to
constitute, at any given period, by far the larger proportion of
the whole submarine area,) there are circumstances accompany-
ing a wreck which favour the conservation of skeletons. For
when the vessel fills suddenly with water, especially in the
night, many persons are drowned between decks and in their
cabins, so that their bodies are prevented from rising again to
the surface. The vessel often strikes upon an uneven bottom
and is overturned, in which case the ballast consisting of sand,
shingle, and rock, or the cargo, frequently composed of heavy
and durable materials, may be thrown down upon the carcasses.
In the case of ships of war, cannon, shot, and other warlike
stores, may press down with their weight the timbers of the
vessel when they decay, and beneath these and the metallic
substances the bones of man may be preserved.

When we reflect on the number of curious monuments con-
signed to the bed of the ocean in the course of every naval
war from the earliest times, our conceptions are greatly
raised respecting the multiplicity of lasting memorials which
man is leaving of his labours. During our last great struggle
with France, thirty-two of our ships of the line went to the
bottom in the space of twenty-two years, besides seven fifty-
gun ships, eighty* six frigates, and a multitude of smaller
vessels. The navies of the other European powers, France,
Holland, Spain, and Denmark, were almost annihilated during
the same period, so that the aggregate of their losses must
have many times exceeded that of Great Britain. In every
one of these ships were batteries of cannon constructed of
iron or brass, whereof a great number had the dates and
places of their manufacture inscribed upon them in letters
cast in metal. In each there were coins of copper, silver, and
often many of gold, capable of serving as valuable historical
monuments; in each were an infinite variety of instruments
of the arts of war and peace, many formed of materials, such
as glass and earthenware, capable of lasting for indefinite ages

Ch. XVI.] AND HIS WORKS, IN SUBAQUEOUS STRATA.

257

when once removed from the mechanical action of the waves,
and buried under a mass of matter which may exclude the
corroding action of sea- water.

But the reader must not imagine that the fury of war is
more conducive than the peaceful spirit of commercial enter-
prise to the accumulation of wrecked vessels in the bed of the
sea. From an examination of Lloyd 1 s lists from the year
1793, to the commencement of 1829, it has appeared that the
number of British vessels alone lost during that period
amounted, on an average, to no less than one and a half
daily * 3 a greater number than we should have anticipated,
although we learn from Moreau's tables that the number of
merchant vessels employed at one time in the navigation of Eng-
land and Scotland, amounts to about twenty thousand, having
one with another a mean burden of one hundred and twenty
tons-f*. Out of five hundred and fifty-one ships of the royal
navy lost to the country during the period above mentioned,
only one hundred and sixty were taken or destroyed by the
enemy, the rest having either stranded or foundered, or having
been burnt by accident J, a striking proof that the dangers of
our naval warfare, however great, may be far exceeded by the
storm, the hurricane, the shoal, and all the other perils of the
deep.

Millions of dollars and other coins have been sometimes
submerged in a single ship, and on these, when they happen to
be enveloped in a matrix capable of protecting them from
chemical changes, much information of historical interest will
remain inscribed and endure for periods as indefinite as have
the delicate markings of zoophytes or lapidified plants in some
of the ancient secondary rocks. In almost every large ship,
moreover, there are some precious stones set in seals, and other
articles of use and ornament composed of the hardest sub-
stances in nature, on which letters and various images are

* I am indebted to my friend Captain W. H. Smyth, R. N.,for this information,
f Csesar Moreau's Tables of the Navigation of Great Britain.
% I give these results on the authority of Captain W. H. Smyth, R. N.
Vol.11. S

258 IMBEDDING OF THE REMAINS OF MAN [Ch.XVI.

carved — engravings which they may retain when included in
subaqueous strata, as long as a crystal preserves its natural
form.

It was a splendid boast, that the deeds of the English
chivalry at Agincourt made Henry's chronicle

— as rich with praise

As is the ooze and bottom of the deep
With sunken wreck and sumless treasuries ;

for it is probable that a greater number of monuments of the
skill and industry of man will, in the course of ages, be col-
lected together in the bed of the ocean, than will be seen at
one time on the surface of the continents.

If our species be of as recent a date as we suppose, it will
be vain to seek for the remains of man and the works of his
hands imbedded in submarine strata, except in those regions
where violent earthquakes are frequent, and the alterations
of relative level so great, that the bed of the sea may have
been converted into land within the historical era. We do not
despair of the discovery of such monuments whenever those
regions which have been peopled by man from the earliest
ages, and which are at the same time the principal theatres of
volcanic action, shall be examined by the joint skill of the
antiquary and the geologist.

There can be no doubt that human remains are as capable
of resisting decay as are the harder parts of the inferior ani-
mals ; and we have already cited the remark of Cuvier, that
" in ancient fields of battle the bones of men have suffered as
little decomposition as those of horses which were buried in
the same grave*." In the delta of the Ganges bones of men
have been found in digging a well at the depth of ninety
feet*}- ; but as that river frequently shifts its course and fills
up its ancient channels, we are not called upon to suppose that
these bodies are of extremely high antiquity, or that they were
buried when that part of the surrounding delta where they
occur was first gained from the sea.

* Vol. i. p. 154. f Hoff., vol. i. p. 379.

Ch. XVI.] AND HIS WORKS, IN SUBAQUEOUS STRATA. 259

Several skeletons of men, more or less mutilated, have been
found in the West Indies, on the north-west coast of the main-
land of Guadaloupe, in a kind of rock which is known to be
forming daily, and which consists of minute fragments of shells
and corals, incrusted with a calcareous cement resembling tra-
vertin, which has also bound the different grains together.
The lens shows that some of the fragments of coral composing
this stone, still retain the same red colour which is seen in the
reefs of living coral which surround the island. The shells
belong to species of the neighbouring sea intermixed with
some terrestrial kinds which now live on the island, and among
them is the Bulimus Guadaloupensis of Ferussac. The human
skeletons still retain some of their animal matter, and all their
phosphate of lime. One of them, of which the head is wanting,
may now be seen in the British Museum, and another in the
Royal Cabinet at Paris. According to Mr. Konig, the rock
in which the former is inclosed is harder under the mason's
saw and chisel, than statuary marble. It is described as form-
ing a kind of glacis, probably an indurated beach, which slants
from the steep cliffs of the island to the sea, and is nearly all
submerged at high tide.

Similar formations are in progress in the whole of the West
Indian archipelago, and they have greatly extended the plain
of Cayes in St. Domingo, where fragments of vases and other
human works have been found at a depth of twenty feet. In
digging wells also near Catania, tools have been discovered in
a rock somewhat similar.

When a vessel is stranded in shallow water, it usually be-
comes the nucleus of a sand bank, as has been exemplified in
several of our harbours, and this circumstance tends greatly to
its preservation. About fifty years ago, a vessel from Purbeck,
laden with three hundred tons of stone, struck on a shoal off the
entrance of Poole harbour and foundered ; the crew were saved,
but the vessel and cargo remain to this day at the bottom.
Since that period the shoal at the entrance of the harbour has
so extended itself in a westerly direction towards Peveril Point

S 2

IMBEDDING OF WORKS OF ART

[Ch.XVL

in Purbeck, that the navigable channel is thrown a mile nearer
that Point '*. The cause is obvious ; the tidal current deposits
the sediment 'with which it is charged around any object which
checks its velocity. Matter also drifted along the bottom is
arrested by any obstacle, and accumulates round it just as the
African sand- winds, before described, raise a small hillock over
the carcasses of every dead camel exposed on the surface of
the desert.

We alluded, in the former volume f , to an ancient Dutch
vessel, discovered in the deserted channel of the river Rother,
in Sussex, of which the oak wood was much blackened, but
its texture unchanged. The interior was filled with fluviatile
silt, as was also the case in regard to a vessel discovered in a
former bed of the Mersey, and another disinterred where the
St. Catherine Docks are excavated in the alluvial plain of the
Thames. In like manner many ships have been found pre-
served entire in modern strata, formed by the silting up of
estuaries along the southern shores of the Baltic, especially in
Pomerania. Between Bromberg and Nakel, for example, a
vessel and two anchors in a very perfect state were dug up
far from the sea j.

At the mouth of a river in Nova Scotia, a schooner of thirty-
two tons, laden with live stock, was lying with her side to the
tide, when the bore, or tidal wave, which rises there about ten
feet in perpendicular height, rushed into the estuary and over-
turned the vessel, so that it instantly disappeared. After the
tide had ebbed, the schooner was so totally buried in the sand,
that the taftrel or upper rail of the deck was alone visible |.
We are informed by Leigh, that, on draining Martin Meer, a
lake eighteen miles in circumference, in Lancashire, a bed of
marl was laid dry, wherein no fewer than eight canoes were
found imbedded. In figure and dimensions they were not
unlike those now used in America. In a morass about nine

* This account I received from the Honourable A. Harris,
t Vol. i. p. 278. $ Hoff., vol. i. p. 368.

§ Silliraan's Gepl. Lectures, p. 78, who cites Fenn,

Ch. XVI.]

IN SUBAQUEOUS STRATA.

261

miles distant from this Meer, a whetstone and an axe of mixed
metal were dug up *. In Ayrshire also, three canoes were
found in Loch Doon some few years ago ; and during the pre-
sent year (1881) four others, each hewn out of separate oak
trees. They were twenty-three feet in length, two and a half in
depth, and nearly four feet in breadth at the stern. In the
mud which filled one of them, was found a war club of oak
and a stone battle-axe.

The only examples of buried vessels to which we can obtain
access, are in such situations as we have mentioned, but we are
unable to examine those which have been subjected to great
pressure, at the bottom of a deep ocean. It is extremely pos-
sible that the submerged wood- work of ships which have sunk
where the sea is two or three miles deep, has undergone
greater chemical changes in an equal space of time, for the
experiments of Scoresby before mentioned show that wood
may at certain depths be impregnated in a single hour with
salt-water, so that its specific gravity is entirely altered.

It may often happen that hot springs charged with carbo-
nate of lime, silex and other mineral ingredients, may issue at
great depths, in which case every pore of the vegetable tissue
may be injected with the lapidifying liquid, whether calcareous
or siliceous, before the smallest decay commences. The con-
version also of wood into lignite is probably more rapid
under such enormous pressure. But the change of the timber
into lignite or coal would not prevent the original form of a
ship from being distinguished, for as we find in strata of the
carboniferous era, the bark of the hollow reed-like trees con-
verted into coal, and the central cavity filled with sandstone,
so might we trace the outline of a ship in coal, and in the in-
durated mud, sandstone, or limestone filling the interior, we
might discover instruments of human art, ballast consisting of
rocks foreign to the rest of the stratum, and other contents of
the ship.

Many of the metallic substances which fall into the waters,
* Leigh's Lancashire, p. 17, A. D. 1700,

262 IMBEDDING OF WORKS OF ART [Ch.XVI.

probably lose, in the course of ages, the forms artificially im-
parted to them ; but under many circumstances these may be
preserved for indefinite periods. The cannon inclosed in a
calcareous rock, drawn up from the delta of the Rhone, which
is now in the museum at Montpellier, might probably have
endured as long as the calcareous matrix ; but even if the me-
tallic matter had been removed and had entered into new com-
binations, still a mould of its original shape would have been
left, corresponding to those impressions of shells which Ave see
in rocks, from which all the carbonate of lime has been sub-
tracted. About the year 1776, says Mr. King, some fisher-
men sweeping for anchors in the Gull stream, (a part of the
sea near the Downs,) drew up a very curious old swivel gun,
near eight feet in length. The barrel, which was about five
feet long, was of brass j but the handle by which it was
traversed, was about three feet in length, and the swivel
and pivot on which it turned were of iron. Around these
latter were formed incrustations of sand converted into a kind
of stone, of an exceeding strong texture and firmness; whereas
round the barrel of the gun, except where it was near adjoin-
ing to the iron, there was no such incrustation, the greater
part of it being clean and in good condition, just as if it had
still continued in use. In the incrusting stone, adhering to
it on the outside, were a number of shells and corallines,
"just as they are often found in a fossil state." These
were all so strongly attached, that it required as much force
to separate them from the matrix, " as to break a fragment off
any hard rock*."

In the year 1745, continues the same writer, the Fox man-
of-war was stranded on the coast of East Lothian and went to
pieces. About thirty-three years afterwards a violent storm
laid bare a part of the wreck, and threw up near the place
several masses a consisting of iron, ropes and balls," covered
over with ochreous sand concreted and hardened into a kind
of stone. The substance of the rope was very little altered.

* Phil. Trans., 1779.

Ch. XVI.]

IN SUBAQUEOUS STRATA.

263

The consolidated sand retained perfect impressions of parts of
an iron ring, " just in the same manner as impressions of
extraneous fossil bodies are found in various kinds of strata'*."

After a storm in the year 1824, which occasioned a consider-
able shifting of the sands near St. Andrew's, in Scotland, a gun
barrel of ancient construction was found, which is conjectured
to have belonged to one of the wrecked vessels of the Spanish
armada. It is now in the museum of the Antiquarian Society
of Scotland, and is encrusted over by a thin coating of sand,
the grains of which are cemented by brown ferruginous matter.
Attached to this coating are fragments of various shells, as of
the common cardium, mya, &c.

Many other examples are recorded of iron instruments taken
up from the bed of the sea near the British coasts, incased by a
thick coating of conglomerate, consisting of pebbles and sand,
cemented by oxide of iron.

Dr. Davy describes in the Philosophical Transactions f , a
bronze helmet of the antique Grecian form, taken up in 1825,
from a shallow part of the sea, between the citadel of Corfu
and the village of Castrades. Both the interior and exterior
of the helmet were partially encrusted with shells, and a deposit
of carbonate of lime. The surface generally, both under the
incrustation and where freed from it, was of a variegated colour,
mottled with spots of green, dirty white, and red. On minute
inspection with a lens, the green and red patches proved to
consist of crystals of the red oxide and carbonate of copper,
and the dirty white chiefly of oxide of tin.

The mineralizing process, says Dr. Davy, which has pro-
duced these new combinations, has in general penetrated very
little into the substance of the helmet. The incrustation and
rust removed, the metal is found bright beneath, in some
places considerably corroded, in others very slightly. It
proves on analysis to be copper alloyed with 18.5 per cent, of
tin. Its colour is that of our common brass, and it possesses
a considerable degree of flexibility : —

* Phil. Trans., vol. Ixix., 1779. f 1826, part ii. p. 55.

CITIES SUBMERGED AND IMBEDDED

[Ch. XVI.

" It is a curious question," he acids, "how the crystals were
formed in the helmet, and on the adhering calcareous deposit.
There being no reason to suppose deposition from solution,
are we not under the necessity of inferring, that the mineraliz-
ing process depends on a small motion and separation of the
particles of the original compound ? This motion may have
been due to the operation of electro- chemical powers which
may have separated the different metals of the alloy."

Effects of the Submersion of Land by Earthquakes.

We have hitherto considered the transportation of plants
and animals from the land by aqueous agents, and their inhu-
mation in lacustrine or submarine deposits, and we may now
inquire what tendency the subsidence of tracts of land by
earthquakes may have to produce analogous effects. Several
examples of the sinking down of buildings and portions of
towns near the shore to various depths beneath the level of
the sea, during subterranean movements, were enumerated in
a former volume, when we treated of the changes brought
about by inorganic causes. The events alluded to were com-
prised within a brief portion of the historical period, and con-
fined to a small number of the regions of active volcanos.
Yet these authentic facts, relating merely to the last century
and a half, gave indications of considerable change which must
have taken place in the physical geography of the globe. If,
during the earthquake of Jamaica in 1692, some of the houses
in Port Royal subsided, together with the ground they stood
upon, to the depth of twenty-four, thirty-six and forty-eight
feet under water, we are not to suppose that this was the only
spot throughout the whole range of the coasts of that island
or the bed of the surrounding sea which suffered similar
depressions. If the quay at Lisbon sank at once to the depth
of six hundred feet in 1755, we must not imagine that this
was the only point on the shores of the peninsula where simi-
lar phenomena might have been witnessed.

If cluring the short period since South America has been.

Ch. XVI.]

IN SUBAQUEOUS DEPOSITS.

263

colonized by Europeans we have proof of alterations of level
at the three principal ports on the western shores, Callao*, Val-
paraiso, and Conception, we cannot for a moment suspect that
these cities so distant from each other have been selected as
the peculiar points where the desolating power of the earth-
quake has expended its chief fury. (i It would be a knowing
arrow that could choose out the brave men from the cowards,"
retorted the young Spartan, when asked if his comrades who
had fallen on the field of battle were braver than he and his
fellow prisoners ; we might in the same manner remark that a
geologist must attribute no small discrimination and malignity
to the subterranean force, if he should suppose it to spare
habitually a line of coast many thousand miles in length, with
the exception of those few spots where populous towns have
been erected. If then we consider how small is the area occu-
pied by the sea-ports of this disturbed region, — points where
alone each slight change of the relative level of sea and land
can be recognized, and reflect on the proofs in our possession
of the local revolutions that have happened on the site of each
port, within the last century and a half, our conceptions must
be greatly exalted respecting the magnitude of the alterations
which the Andes may have undergone even in the course of
the last six thousand years.

We cannot better illustrate the manner in which a large
extent of surface may be submerged, so that the terrestrial
plants and animals may become imbedded in subaqueous strata,
than bjr referring to the earthquake of Cutch, in 1819, alluded
to by us in a former volume f. We shall enter somewhat
more fully into details concerning that catastrophe than the

* It is well known that during the great earthquake of Lima, in 174G, part of the
promontory south of Callao sank down, and it is a common story at Lima that its
former termination became the present isle of San Lorenzo, between which and
the main land there is now a navigable channel. The submerged arches of a
church, and the present position of other buildings, are said to indicate that the
site of Callao underwent, during the earthquakes, a change of level ; an interesting
fact, the evidences of which we hope will soon be examined by some of our naval
officers, and other intelligent persons frequenting that port.

f Vol, i. p. 405.

266

RECENT ALTERATIONS OF LEVEL

[Ch. XVI.

immediate subject of the present chapter might require, in
order to lay before the reader the information obtained during
the recent survey of Cutch.

The published account of Lieutenant A. Burnes*, who ex*
amined that portion of the delta of the Indus in 1826 and 1829,
confirms the facts before enumerated by us, and furnishes the
following important particulars. The tract around Sindree,
which subsided during the earthquake in June, 1819, was con-
verted from dry land into sea in the course of a few hours, the
new-formed mere extending for a distance of sixteen miles on
each side of the fort, and probably exceeding in area the lake of
Geneva. Neither the rush of the sea into this new depression,
nor the movement of the earthquake, threw down the small fort
of Sindree, the interior of which is said to have become a tank,
the water filling the space within the walls, and the four towers
continuing to stand, so that on the day after the earthquake
the people in the fort who had ascended to the top of one of
the towers saved themselves in boats. Immediately after the
shock the inhabitants of Sindree saw, at the distance of five
miles from their village, a long elevated mound, where pre-
viously there had been a low and perfectly level plain. To
this uplifted tract they gave the name of u Ullah bund," or
" the Mound of God," to distinguish it from an artificial bar-
rier previously thrown across an arm of the Indus.

It is already ascertained that this newly raised country is
upwards of fifty miles in length from east to west, running
parallel to that line of subsidence before mentioned, which
caused the grounds around Sindree to be flooded. The range
of this elevation extends from Puchum island towards Gharee;
its breadth from north to south is conjectured to be in some
parts sixteen miles, and its greatest ascertained height above
the original level of the delta is ten feet, an elevation which
appears to the eye to be very uniform throughout.

For several years after the convulsion of 1819, the course of
the Indus was very unsettled, and at length in 1826, the river
burst its banks above Sinde^ and forcing its way in a more

* Now in the Library of the Royal Asiatic Society.

Ch. XVI.]

IN THE DELTA OF THE INDUS.

267

direct course to the sea, cut right through the " Ullah bund,"
whereby a natural section was obtained. In the perpendicular
cliffs thus laid open, Lieutenant Burnes found that the up-
raised land consisted of beds of clay filled with shells. The
new channel of the river, where it intersected the " bund," was
eighteen feet deep, and during the swells in 1826, it was two
or three hundred yards in width, but in 1828 the channel was
still further enlarged. The Indus, when it first opened this
new passage, threw such a body of water into the new lake or
salt lagoon of Sindree, that it became fresh for many months,
but it had recovered its saltness in 1828, when the supply of
river-water was less copious, and finally it became more salt
than the sea, in consequence, as the natives suggested to Lieu-
tenant Burnes, of the saline particles with which H the Runn
of Cutch" is impregnated.

Besides Ullah bund, there appears to have been another
elevation south of Sindree, parallel to that before mentioned,
respecting which, however, no exact information has yet been
communicated. There is a tradition of an earthquake, which,
about three centuries before, upheaved a large area of the bed
of the sea, and converted it into land in the district now called
C( the Runn," so that numerous harbours were laid dry and
ships were wrecked and engulphed ; in confirmation of which
account it was observed in 1819, that in the jets of black
muddy water thrown out of fissures in that region, there were
cast up numerous pieces of wrought iron and ship nails.

We must not conclude without alluding to a moral pheno-
menon connected with this tremendous catastrophe, which we
regard as highly deserving the attention of geologists. The
author above cited states that " these wonderful events passed
unheeded by the inhabitants of Cutch," for the region con-
vulsed, though once fertile, had for a long period been reduced
to sterility by want of irrigation, so that the natives were
indifferent as to its fate. Now it is to this profound apathy,
which all but highly civilized nations feel in regard to physical
events, not having an immediate influence on their worldly
fortunes, that we must ascribe the extraordinary dearth of

268

EFFECTS OF EARTHQUAKES

[Ch. XVI.

historical information concerning changes of the earth's surface,
which modern observations show to be by no means of rare
occurrence in the ordinary course of nature.

It is stated that, for some years after the earthquake, the
withered tamarisks and other shrubs protruded their tops
above the waves, in parts of the submerged tract around Sin-
dree ; but after the flood of 1826 they were seen no longer.
Every geologist will at once perceive that forests sunk by such
subterranean movements, may become imbedded in subaqueous
deposits both fluvatile and marine, and the trees may still
remain erect, or sometimes the roots and part of the trunks
may continue in their original position, while the current may
have broken off, or levelled with the ground, their upper stems
and branches.

But although a certain class of geological phenomena may be
referred to the repetition of such catastrophes, we must hesitate
before we call in to our aid the action of earthquakes, to explain
what have been termed submarine forests, observed at various
points around the shores of Great Britain. We have already
hinted that the explanation of some of these may be sought in
the encroachments of the sea, in estuaries, and the varying level
of the tides, at distant periods on the same parts of our coast*.
After examining, in 1829, the so called submarine forest of
Happisborough in Norfolk, I found that it was nothing more
than a tertiary lignite of the " Crag " period, which becomes
exposed in the bed of the sea as soon as the waves sweep away
the superincumbent strata of bluish clay. So great has been
the advance of the sea upon our eastern shores within the
last eight centuries, that whenever we find a mass of sub-
merged timber near the sea side, or at the foot of the existing
cliffs which we cannot suppose to be a mere accumulation of
drift, vegetable matter, we should endeavour to find a solution
of the problem, by reference to any cause rather than an earth-
quake. For we can scarcely doubt that the present outline of
pur coast, the shape of its estuaries, and the formation of its
cliffs are of very modern date, probably within the human

* Vol. i. pi 270,

Ch. XVl.] IN IMBEDDING CITIES AND FORESTS. 269

era, whereas we have no reason whatever to imagine that this
part of Europe has been agitated by subterranean convulsions,
capable of altering the relative level of land and sea, at so
extremely recent a period.

Some of the buildings which have at different times sub-
sided beneath the level of the sea, have been immediately
covered up to a certain extent with strata of volcanic matter
showered down upon them. Such was the case at Tomboro
in Sumbawa, in the present century, and at the site of the
Temple of Serapis, in the environs of Fuzzuoli, probably in
the 12th century. The entrance of a river charged with sedi-
ment in the vicinity, may still more frequently occasion the
rapid envelopement of buildings in regularly stratified forma-
tions. But if no foreign matter be introduced, the buildings
when once removed to a depth where the action of the waves
is insensible, and where no great current happens to flow,
may last for indefinite periods, and be as durable as the floor
of the ocean itself, which may often be composed of the very
same materials. There is no reason to doubt the tradition
mentioned by the classic writers, that the submerged Grecian
towns of Bura and Helice were seen under water ; and I am
informed by an eye-witness that eighty-eight years after the
convulsion of 1692, the houses of Port Iioyal were still visible
at the bottom of the sea

* Admiral Sir Charles Hamilton frequently saw the submerged houses of
Port Royal in the year 1780, in that part of the harbour which lies between the town
and the usual anchorage of men-of-war. Bryan Edwards also says in his History
of the West Indies, (vol. i. p. 235, oct. ed. 3 vols., 1801,) that in 1793 the
ruins were visible in clear weather from the boats which sailed over them. I
regret to see that Mr. De la Beche, in his valuable Manual of Geology, (p. 130,)
has evinced so much scepticism in regard to the accuracy of the evidence collected
by Sir Hans Sloane, respecting the catastrophe of Port Royal, a town with which
Sir H. was well acquainted. To me the original documents collected imme-
diately after the event, appear to bear the intrinsic stamp of truth. The
objection against the fact alleged by several eye-witnesses, " that the chimney tops
alone of many houses were seen after the shocks, as well as the masts of vessels
just projecting above the waves," is quite futile. Perhaps the chimnejrs in Port
Royal might in 1692, have been confined to low kitchens, as Mr. De la Beche says
they now are, and they might only have been fifteen or twenty feet in height, still
the same, subsidence which reduced them to the level of the water might cause the

&70 RECENT ORIGIN OF MAN. [Ch. XVI.

We cannot conclude this chapter without recalling to the
reader's mind a memorable passage written by Berkely a cen-
tury ago, in which he inferred, on grounds which may be
termed strictly geological, the recent date of the creation of
man. " To any one," says he, i( who considers that on dig-
ging into the earth such quantities of shells, and in some places
bones and horns of animals are found sound and entire, after
having lain there in all probability some thousands of years ;
it should seem probable that guns, medals and implements in
metal or stone might have lasted entire, buried under ground
forty or fifty thousand years if the world had been so old.
How comes it then to pass that no remains are found, no anti-
quities of those numerous ages preceding the Scripture accounts
of time ; that no fragments of buildings, no public monuments,
no intaglias, cameos, statues, basso-relievos, medals, inscrip-
tions, utensils, or artificial works of any kind are ever disco-
vered, which may bear testimony to the existence of those
mighty empires, those successions of monarchs, heroes, and
demi-gods for so many thousand years ? Let us look forward
and suppose ten or twenty thousand years to come, during
which time we will suppose that plagues, famine, wars and
earthquakes shall have made great havoc in the world, is it not
highly probable that at the end of such a period, pillars, vases,
and statues now in being of granite, or porphyry, or jasper,
(stones of such hardness as we know them to have lasted two
thousand years above ground, without any considerable altera-
tion) would bear record of these and past ages ? Or that some
of our current coins might then be dug up, or old walls and
the foundations of buildings shew themselves, as well as the
shells and stones of the primeval ivorld, which are preserved
down to our times * ?"

ships which were previous/// floating to disappear entirely, with the exception of
the tops of their masts. Besides, we infer from the various narratives, that the
subsidences were very unequal at different neighbouring points.

I have great pleasure in stating, that on my requesting Mr. De la Beche to send
me more exact particulars, respecting the present state of the harbour of Port
Royal, he has ordered a survey to be made.

* Alciphron, or the Minute Philosopher, vol. ii. pp. 84, 85. 1732.

Ch. XVI.]

RECENT ORIGIN OF MAN.

That many signs of the agency of man would have lasted at
least as long as u the shells of the primeval world," had our
race been so ancient, we are as fully persuaded as Berkely ;
and we anticipate with confidence that many edifices and im-
plements of human workmanship, and the skeletons of men,
and casts of the human form, will continue to exist when a
great part of the present mountains, continents, and seas have
disappeared. Assuming the future duration of the planet to
be indefinitely protracted, we can foresee no limit to the per-
petuation of some of the memorials of man, which are continu-
ally entombed in the bowels of the earth or in the bed of the
ocean, unless we carry forward our views to a period sufficient
to allow the various causes of change both igneous and aqueous,
to remodel more than once the entire crust of the earth. One
complete revolution will be inadequate to efface every monu-
ment of our existence, for many works of art might enter again
and again into the formation of successive eras, and escape
obliteration even though the very rocks in which they had
been for ages imbedded were destroyed, just as pebbles in-
cluded in the conglomerates of one epoch often contain the or-
ganized remains of beings which flourished during a prior era.

Yet it is no less true, as a late distinguished philosopher
has declared, " that none of the works of a mortal being can be
eternal *." They are in the first place wrested from the hands
of man, and lost as far as regards their subserviency to his use,
by the instrumentality of those very causes which place them
in situations where they are enabled to endure for indefinite
periods. And even when they have been included in rocky
strata, when they have been made to enter as it were into
the solid framework of the globe itself, they must nevertheless
eventually perish, for every year some portion of the earth's
crust is shattered by earthquakes or melted by volcanic fire,
or ground to dust by the moving waters on the surface. " The
river of Lethe," as Bacon eloquently remarks, " runneth as
well above ground as below f

* Davy, Consolations in Travel, p. 276.
f Essay on the Vicissitude of Things.

CHAPTER XVII.

Imbedding of aquatic species in subaqueous strata — Inhumation of fresh-watef
plants and animals — Shell marl — Fossilized seed-vessels and stems of Chara
i — Recent deposits in the American lakes — Fresh-water species drifted into seas
and estuaries — Lewes levels — Alternations of marine and fresh-water strata,
how caused — Imbedding of marine plants and animals — Cetacea stranded on
our shores — Their remains should be more conspicuous in marine alluvium than
the bones of land quadrupeds — Liability of littoral and estuary testacea to be
swept into the deep sea — Effects of a storm in the Frith of Forth — Burrowing
shells secured from the ordinary action of waves and currents — Living testacea
found at considerable depths.

We have hitherto treated of the imbedding of terrestrial plants
and animals, and of human remains in the deposits that are
now forming beneath the waters, and we come next to con-
sider in what manner aquatic species may be entombed in
strata, formed in their own element.

Imbedding of Fresh-water Plants and Animals.

The remains of species belonging to those genera of the
animal and vegetable kingdoms, which are more or less exclu-
sively confined to fresh-water, are for the most part preserved
in the beds of lakes or estuaries, but they are oftentimes swept
down by rivers into the sea, and there intermingled with the
exuviae of marine races. The phenomena attending their in-
humation in lacustrine deposits, may be sometimes revealed
to our observation by the drainage of small lakes, such as are
those in Scotland which have been laid dry for the sake of
obtaining shell marl for agricultural uses.

In these recent formations, as seen in Forfarshire, two or
three beds of calcareous marl are sometimes observed separated
from each other by layers of drift peat, sand, or fissile clay.
The marl often consists almost entirely of an aggregate of
shells of the genera limnea, planorbis, valvata, and cyclas, with
some few others, species of all which now exist in Scotland. A
considerable proportion of the testacea appear to have died

Ch. XVII.]

IMBEDDING OF F RE SIFT-WATER PLANTS.

273

very young, and few of the shells are of a size which indicates
their having attained a state of maturity. The shells are
sometimes entirely decomposed, forming a pulverulent marl ;
sometimes they are in a state of good preservation. They are
frequently intermixed with stems of charae and other aquatic
vegetables, which are matted together and compressed, forming
laminse often as thin as paper.

As the chara is an aquatic plant, which occurs frequently
fossil in formations of different eras, and is often of much im-
portance to the geologist in characterizing entire groups of
strata, we shall describe the manner in which the recent species
have been found in a petrified state. They occur in one of the
lakes of Forfarshire, inclosed in nodules, and sometimes in a
continuous stratum of a kind of travertin.

The seed-vessel of these plants is remarkably tough and
hard, and consists of a membranous nut covered by an integu-
ment (fig. d diagram No. 2,) both of which are spirally striated
or ribbed. The integument is composed of five spiral valves^

(No. 2.)

Seed-vessel of Chara hispida.

(a) Part of the stem with the seed-vessel attached. Magnified.
(/>) Natural size of the seed-vessel.

found in the Scotch marl-lakes. Magnified,
(rf) Section showing the nut within the integument!
(e) Lower end of the integument to which the stem was attached.
Vol. II. T

£74 IMBEDDING OF FRESH-WATER PLANTS. [Ch. XVII.

of a quadrangular form (fig. g). In Chara hispida which
abounds in the lakes of Forfarshire, and which has become
fossil in the Bakie Loch, each of the spiral valves of the seed-
vessel turns rather more than twice round the circumference,
the whole together making between ten and eleven rings. The
number of these rings differs greatly in different species, but in
the same appears to be very constant.

The stems of charse occur fossil in the Scotch marl in great
abundance. In some species, as in Chara hispida, the plant
when living contains so much carbonate of lime in its vege-
table organization, independently of calcareous incrustation,
that it effervesces strongly with acids when dried. The stems
of Chara hispida are longitudinally striated, with a tendency to
be spiral. These striae, as appears to be the case with all
chara?, turn always like the worm of a screw from right to left,
while those of the seed-vessel wind round, in a contrary direc-
tion. A cross section of the stem exhibits a curious structure,
for it is composed of a large tube surrounded by smaller tubes,
(diagram No. 3. fig. b, c,) as is seen in some extinct, as well

(No. 3.)

Stem and tranches of Chara hispida,

(a) Stem and branches of the natural size.
(6) Section of the stem magnified.

Ch. XVII.] IMBEDDING OF FRESH- WATER SPECIES.

as recent species. In the stems of several species, however,
there is only a single tube*.

The valves of a small animal called cypris (C. ornata
Lam.) occur completely fossilized like the stems of charas, in
the Scotch travertin above mentioned. This cypris inhabits
the lakes and ponds of England where it is not uncommon.
Species of the same genus also occur abundantly in ancient
fresh-water formations.

The recent strata of lacustrine origin above alluded to are of
very small extent, but analogous deposits on the grandest scale
have been formed in the great lakes of North America. By
the subsidence of the waters of Lakes Superior and Huron,
occasioned probably by the partial destruction of their barriers
at some unknown period, beds of sand one hundred and fifty
feet thick are exposed, below which are seen beds of clay, in-
closing shells of the very species which now inhabit the lake f .

But no careful examination appears as yet to have been
made of recent fresh-water formations within the tropics,
where the waters teem with life, and where in the bed of a
newly drained lake the remains of the alligator, crocodile
tortoise, and perhaps some large fish might be discovered.

Imbedding of Fresh-water Species in Estuary and Marine

Deposits.

We have sometimes an opportunity of examining the de
posits which within the historical period have silted up some
of our estuaries ; and excavations made for wells and other
purposes, where the sea has been finally excluded, enable us
to observe the state of the organic remains in these tracts.
The valley of the Ouse between Newhaven and Lewes is one
of several estuaries from which the sea has retired within the
last seven or eight centuries ; and here it appears from the
researches of Mr. Mantell, that strata of thirty feet and
upwards in thickness have accumulated. At the top, beneath

* Geol. Trans., vol. ii., second series, p. 73. On Fresh-water Marl, &c. By
C. Lyell, Esq. f Dr. Bigsby's Journal of Science, &c. No. 37, pp. 262, 263.

T 2

276 IMBEDDING OF F ItESFi-W ATE R SPEC IKS. [Cli. XVII.

the vegetable soil, is a bed of peat about five feet thick, en-
closing many trunks of trees. Next below is a stratum of
blue clay containing fresh-water shells of about nine species,
such as now inhabit the district. Intermixed with these was
observed the skeleton of a deer. Lower down, the layers of
blue clay contain with the above-mentioned fresh-water shells
several marine species well known on our coast. In the lowest
beds, often at the depth of thirty-six feet, these marine testacea
occur without the slightest intermixture of fluviatile species,
and amongst them the skull of the narwal, or sea-unicorn
(Monodon mo7ioceros), has been detected. Underneath all
these deposits is a bed of pipe-clay, derived from the sub-
jacent chalk*.

If we had no historical information respecting the former
existence of an inlet of the sea in this valley, and of its gradual
obliteration, the inspection of the section above described
would show, as clearly as a written chronicle, the following
sequence of events. First, there was a salt-water estuary
peopled for many years by species of marine testacea identical
with those now living, and into which some of the larger
cetacea occasionally entered. Secondly, the inlet grew shal-
lower, and the water became brackish, or alternately salt and
fresh, so that the remains of fresh-water and marine shells were
mingled in the blue argillaceous sediment of its bottom.
Thirdly, the shoaling continued until the river water prevailed,
so that it was no longer habitable by marine testacea, but fitted
only for the abode of fluviatile species and aquatic insects.
Fourthly, a peaty swamp or morass was formed where some
trees grew, or, perhaps, were drifted during floods, and where
terrestrial quadrupeds were mired. Finally, the soil being
only flooded by the river at distant intervals, became a verdant
meadow.

W e have stated when speaking of the delta of the Ganges,
that on the sea-coast there are eight great openings, each of

* Mantell, Geol. of Sussex, p. 285 ; also Catalogue of Org. Rem., Geol. Traus.,
y. iii., part I, p. 201. Second Series.

Ch. XVII.] IN ESTUARY AND MARINE DEPOSITS.

277

which has evidently, at some ancient periods, served in its turn
as the principal channel of discharge. Now as the base of the
delta is two hundred miles in length, it must happen that as
often as the great volume of river-water is thrown in by a new
mouth, the waters of the sea will at one point be converted
from salt to fresh, and at another from fresh to salt; for, with
the exception of those parts where the principal discharge
takes place, the salt-water not only washes the base of the
delta, but enters far into every creek and lagoon. It is evident
then that repeated alternations of beds containing fresh- water
shells, with others filled with corals and marine exuvias, may
here be formed, and each series may be of great thickness, as
the sea on which the Gangetic delta gains, is of considerable
depth, and intervals of centuries elapse between each alteration
in the course of the principal stream.

It is evident that analogous phenomena must sometimes be
occasioned by such alternate elevation and depression of the
land as was shown in the last chapter to be taking place in the
delta of the Indus. But the subterranean movements affect
but a small number of the deltas formed at one period on the
globe ; whereas, the silting up of some of the arms of great
rivers and the opening of others, and the consequent variation
of the points at which the chief volume of their waters enters
the sea, are phenomena common to almost every delta.

The variety of species of testacea contained in the recent
calcareous marl of Scotland, before mentioned, is very small,
but the abundance of individuals is extremely great, a circum-
stance which characterizes fresh-water formations in general as
compared to marine ; for in the latter, as is seen on sea-
beaches, coral reefs, or in the bottom of seas examined by
dredging, wherever the individual shells are exceedingly
numerous there rarely fails to be a vast variety of species.

Imbedding of the Remains of Marine Plants and Animals.

Marine Plants. — We have alluded to the large banks of
drift sea-weed which occur on each side of the equator in the

IMBEDDING OF THE REMAINS

[Ch. XVII.

Atlantic, Pacific, and Indian oceans % These when they sub-
side may often produce considerable beds of vegetable matter.
In Holland submarine peat is derived from fuci, and on parts
of our own coast from Zostera marina. In places where
alga? do not generate peat, they may nevertheless leave traces
of their form imprinted on argillaceous and calcareous mud, as
they are usually very tough in their texture.

Cetacea. — It is not uncommon for the larger cetacea, which
can only float in a considerable depth of water, to be carried
during storms or high tides into estuaries, or upon low shores,
where, upon the retiring of high water, they are stranded.
Thus a narwal (Monodon monoceros) was found on the beach
near Boston, in Lincolnshire, in the year 1800,, the whole of
its body buried in the mud. A fisherman going to his boat
saw the horn and tried to pull it out, when the animal began
to stir itself j-. An individual of the common whale (Baloena
my sticetus) , which measured seventy feet, came ashore near
Peterhead, in 1682. Many individuals of the genus Balae-
noptera have met the same fate. We may content ourselves
with referring to those cast on shore near Burnt Island, and
at Alloa, recorded by Sibbald and Neill. The other indi-
vidual mentioned by Sibbald, as having come ashore at Boyne,
in Banffshire, was probably a Razor-back. Of the genus Ca-
todon (Cachalot), Ray mentions a large one stranded on the
west coast of Holland in 1598, and the fact is also commemo-
rated in a Dutch engraving of the time of much merit. Sib-
bald, too, records that a herd of Cachalots, upwards of one
hundred in number, were found stranded at Kairston, Orkney J.
The dead bodies of the larger cetacea are sometimes found
floating on the surface of the waters, as was the case with the
immense whale exhibited in London in 1831. And the carcass
of a sea-cow or Lamantine (Halicorci) was, in 1785, cast ashore
near Leith. We might enumerate many more examples de-

* Page 78.

t Fleming's Brit. Animals, p.' 37; in which work may be seen many other
cases enumerated,

Ch. XVII.] OF MARINE PLANTS AND ANIMALS, 270

rived from foreign as well as British shores, but the facts above
cited will suffice to show that such occurrences are not rare.

To some accidents of this kind, we may refer the position of
the skeleton of a whale seventy-three feet long, which was
found at Airthrey, on the Forth near Alloa, imbedded in clay
twenty feet higher than the surface of the highest tide of the
river Forth at the present day. From the situation of the
Roman station and causeways at a small distance from the
spot, it is concluded that the whale must have been stranded
there at a period prior to the Christian era*.

Other fossil remains of this class have also been found in estua-
ries, known to have been silted up in recent times, one example
of which we have already mentioned near Lewes, in Sussex.
When we reflect on the facility with which these marine mam-
malia are thus shown to run aground upon shoals, even when
there have been no great convulsions, such as hurricanes or
earthquakes extending under the ocean, but merely such dis-
turbances as the tides and storms of our seas may cause, we
may be better enabled to form a sound opinion, in regard to
the probability of certain geological theories, which have ac-
quired no small share of popularity. It has been suggested,
that if the ocean, displaced by the sudden upheaving of some
great mountain-chain, such as the Andes, should make a tran-
sient passage over the land, a covering of alluvium might be
left strewed over the hills and valleys, and that, in this allu-
vium, might be contained the remains of mammalia exclusively
terrestrial. The skeleton of the gigantic whale, the long horn
of the narwal (harder than ivory), the strong grinders of the
lamantine, these and other marine relics of the era

Omne cum Proteus pecus egit altos
Visere montes,

might, we are told, be entirely wanting. Not one of them
would be conspicuous amongst the refuse of the ec bated and
retiring flood," but instead of them we should discover the
bones, tusks, and teeth of the elephant or rhinoceros, the hip-

* Quart. Journ. of Lit, Sci.> &c. No. 15, p. 172. Oct, 1819.

280

IMBEDDING OP MARINE TESTACEA.

[Ch. XVII.

popotamus, ox, and horse, with occasionally, perhaps, some
intermixture of terrestrial and lacustrine shells ! Such, we are
taught, would he the memorials of a marine deluge sweeping
over our continents ! We are, however, willing to admit that
they who invent causes without reference to known analogies,
are guilty of no inconsistency when they claim some license in
the use which they make of their extraordinary agents. If we
allow them to " call spirits from the vasty deep " to do their
bidding, and to uplift colossal chains, like the Andes, suddenly
within the historical era, we must not complain that the effects
of such mighty powers are not always such as the analogy of
the ordinary laws of Nature would have led us to anticipate.

Marine Testacea.- — The aquatic animals and plants which
inhabit an estuary are liable, like the trees and land animals
which people the alluvial plains of a great river, to be swept
from time to time far into the deep. For as a river is per-
petually shifting its course, and undermining a portion of its
banks with the forests which cover them, so the marine current
alters its direction from time to time, and bears away the banks
of sand and mud, against which; it turns its force. These
banks may consist in great measure of shells peculiar to shallow,
and sometimes brackish water, which may have been accumu-
lating for centuries, until at length they are carried away and
spread out along the bottom of the sea, at a depth at which
they could not have lived and multiplied. Thus littoral and
estuary shells are more frequently liable even than fresh-
water species, to be intermixed with the exuvias of pelagic
tribes.

After the late storm of February 4, 1831, when several
vessels were wrecked in the estuary of the Forth^ the current
was directed against a bed of oysters with such force, that
great heaps of them were thrown alive upon the beach, and
remained above high-water mark. Many of these oysters, as
also the common whelks (buccina), which were thrown up
with them, in a living state, were worn by the long attrition of
sand which had passed over them as they lay in their native

Ch. XVII.]

IMBEDDING OF MARINE TESTACE A.

281

bed, and which had evidently not resulted from the mere
action of the tempest by which they had been cast ashore.

From these facts we may learn that the union of the two
parts of a bivalve shell does not prove that it may not have
been transported to a certain distance; and when we find shells
worn, and with all their prominent parts rubbed off, they may
still have been imbedded where they grew.

It sometimes appears extraordinary when we observe the
violence of the breakers on our coast, and see the strength of
the current in removing cliffs and sweeping out new channels,
that many tender and fragile shells should inhabit the sea in
the immediate vicinity of this turmoil. But a great number
of the bivalve testacea, and many also of the turbinated uni-
valves burrow in sand or mud. The solen and the cardium,
for example, which are usually found in shallow water near the
shore, pierce through a soft bottom without injury to their
shells; and the pholas can drill a cavity through mud of con-
siderable hardness. The species of these and many other
tribes can sink, when alarmed,, with considerable rapidity,
often to the depth of several feet, and can also penetrate up-
wards again to the surface if a mass of matter be heaped upon
them. The hurricane, therefore, may expend its fury in vain,
and may sweep away even the upper part of banks of sand or
mud, or may roll pebbles over them, and yet these testacea
may remain below secure and uninjured.

We have already stated that at the depth of nine hundred
and fifty fathoms between Gibraltar and Ceuta, Captain Smyth
found a gravelly bottom, with fragments of broken shells
carried thither probably from the comparatively shallow parts
of the neighbouring straits, through which a powerful current
flows. Beds of shelly sand might here, in the course of ages,
be accumulated several thousand feet thick. But, without the
aid of the drifting power of a current, shells may accumulate
in the spot where they live and die, at great depths from the
surface, if sediment be thrown down upon them ; for, even in
our own colder latitudes, the depths at which living marine

282 IMBEDDING OF MARINE TESTACEA. fCh. XVII.

animals abound is very considerable. Captain Vidal ascer-
tained, by soundings lately made off Tory island, on the north-
west coast of Ireland, that Crustacea, star-fish, and testacea,
occurred at various depths between fifty and one hundred
fathoms ; and in the tropics testacea and zoophytes have been
found still deeper.

During the survey of the west coast of Africa, now in pro-
gress, Captain Belcher found, by frequent soundings between
the twenty-third and twentieth degrees of north latitude, that
the bottom of the sea at the depth of from twenty to about fifty
fathoms, consists of sand, with a great intermixture of shells
often entire, but sometimes finely comminuted. Between the
eleventh and ninth degrees of north latitude, on the same
coast, at soundings varying from twenty to about eighty
fathoms, he brought up abundance of corals and shells mixed
with sand. These also were in some parts entire, and in others
worn and broken.

In all these cases it is only necessary that there should be
some deposition of sedimentary matter, however minute, such
as may be supplied by rivers or currents preying on a line of
cliffs, and stratified formations, hundreds of feet in thickness,
will result in the course of ages, containing throughout organic
remains, in a more or less perfect state of preservation.

CHAPTER XVIII.

Formation of coral reefs — They are composed of shells as well as corals — Conversion
of a submerged reef into an island — Extent and thickness of coral formations —
The Maldiva isles — Growth of coral not rapid — Its geological importance — Cir-
cular and oval forms of coral islands — Shape of their lagoons — Causes of their
peculiar configuration — Openings into the lagoons — Why the windward side both
in islands and submerged reefs is higher than the leeward — Stratification of coral
formations — Extent of some reefs in the Pacific — That the subsidence by earth-
quakes in the Pacific, exceeds the elevation due to the same cause — Elizabeth,
or Henderson' s Island — Coral and shell limestones now in progress, exceed in
area any known group of ancient rocks — The theory that all limestone is of
animal origin considered — The hypothesis that the quantity of calcareous matter
has been and is still on the increase, controverted.

Corals and Coral reefs.

The powers of the organic creation in modifying the form and
structure of those parts of the earth's crust, which may be
said to be undergoing repair, or where new rock-formations
are continually in progress, are most conspicuously displayed
in the labours of the coral animals. We may compare the
operation of these zoophytes in the ocean, to the effects pro-
duced on a smaller scale upon the land, by the plants which
generate peat. In the case of the Sphagnum, the upper part
vegetates while the lower portion is entering into a mineral
mass, where the traces of organization usually remain, but in
which life has entirely ceased. In the corals, in like manner,
the more durable materials of the generation that has passed
away, serve as the foundation on which living animals are con-
tinuing to rear a similar structure.

The calcareous masses usually termed coral reefs, are by no
means exclusively composed of zoophytes, but also a great
variety of shells ; some of the largest and heaviest of known
species contributing to augment the mass. In the south Pacific,
great beds of oysters, mussels, pinncs marines, and other shells,
cover in great profusion almost every reef ; and, on the beach

284 FORMATION OF CORAL ISLANDS. [Ch. XVIII.

of coral islands, are seen the shells of echini and the broken
fragments of crustaceous animals. Large shoals of fish also
are discernible through the clear blue water, and their teeth
and hard palates are probably preserved, although a great por-
tion of their soft cartilaginous bones may decay.

Of the numerous species of zoophytes which are engaged in
the production of coral banks, some of the most common be-
long to the genera Meandrina, Caryophyllia and Astrea, but
especially the latter.

The reefs, which just raise themselves above the level of the
sea, are usually of a circular or oval form, and are surrounded
by a deep and often unfathomable ocean. In the centre of
each, there is usually a comparatively shallow lagoon where
there is still water, and where the smaller and more delicate
kinds of zoophytes find a tranquil abode, while the more strong
species live on the exterior margin of the isle, where a great
surf usually breaks. When the reef, says M. Chamisso, a
naturalist who accompanied Kotzebue, is of such a height
that it remains almost dry at low water, the corals leave off
building. A continuous mass of solid stone is seen composed
of the shells of molluscs and echini, with their broken off
prickles and fragments of coral, united by the burning sun,
through the medium of the cementing calcareous sand, which
has arisen from the pulverization of shells. Fragments of
coral limestone are thrown up by the waves, until the ridge
becomes so high, that it is covered only during some seasons
of the year by the high tides. The heat of the sun often
penetrates the mass of stone when it is dry, so that it splits in
many places. The force of the waves is thereby enabled to
separate and lift blocks of coral, frequently six feet long and
three or four in thickness, and throw them upon the reef.
" After this the calcareous sand lies undisturbed, and offers to
the seeds of trees and plants cast upon it by the waves, a soil
upon which they rapidly grow, to overshadow its dazzling
white surface. Entire trunks of trees, which are carried by
the rivers from other countries and islands, find here, at

Ch. XVIII.]

EXTENT OF CORAL REEFS.

285

length, a resting-place after their long wanderings : with these
come some small animals, such as lizards and insects, as the
first inhabitants. Even before the trees form a wood, the
sea-birds nestle here ; strayed land-birds take refuge in the
bushes ; and, at a much later period, when the work has been
long since completed, man also appears, builds his hut on
the fruitful soil formed by the corruption of the leaves of the
trees, and calls himself lord and proprietor of this new crea-
tion *."

The Pacific ocean throughout, a space comprehended be-
tween the thirtieth parallel of latitude on each side of the
equator, is extremely productive of coral. The Arabian gulf
is rapidly filling with the same, and it is said to abound in
the Persian gulf. Between the coast of Malabar and that of
Madagascar, there is also a great sea of coral. Flinders
describes an unbroken reef three hundred and fifty miles in
length, on the east coast of New Holland; and, between that
country and New Guinea, Captain P. King found the coral
formations to extend throughout a distance of seven hundred
miles, interrupted by no intervals exceeding thirty miles in
length.

The chain of coral reefs and islets, called the Maldivas,
situated in the Indian ocean to the south-west of Malabar,
form a chain four hundred and eighty geographical miles in
length, running due north and south. It is composed through-
out of a series of circular assemblages of islets, the larger
groups being from forty to fifty miles in their longest diameter'.
Captain Horsbui'gh, whose chart of these islands is subjoined,
informs me that outside of each circle or atoll, as it is termed,
there are coral reefs sometimes extending to the distance of
two or three miles, beyond which there are no soundings at
immense depths. But in the centre of each atoll there is
a lagoon from fifteen to twenty fathoms deep. In the channels
between the atolls, no soundings have been obtained at the
depth of one hundred and fifty fathoms.

The Laccadive islands run in the same line with the Mal-
* Kotzebue's Voyages, 1815.18, vol, iii. p. 331 — 3.

286

LINEAR DIRECTION OF CORAL ISLES. [Ch. XVIII.

MALDIVA. ISLES.

One

^- a 7udf degree
Channel,

divas, on the north, as do the isles
of the Chagos Archipelago, on the
south., so that these may be con-
tinuations of the same chain of
submarine mountains, crested in
a similar manner by coral lime-
stone. It would be rash to hazard
the hypothesis, that they are all
the summits of volcanos, yet we
might imagine, that if Java and
Sumatra were submerged, they
would give rise to a somewhat
similar shape in the bottom of the
sea; for the volcanos of those
islands observe a linear direction,
and are often separated from each
other by intervals, corresponding
to the atolls of the Maldivas; and
as they rise to various heights,
from five to ten thousand feet
above their base, they might leave
an unfathomable ocean in the in-
termediate spaces.

In regard to the thickness of
the masses of coral, MM. Quoy
and Gaimard are of opinion, that
the species which contribute most
actively to the formation of solid
masses do not grow where the
water is deeper than twenty-five
or thirty feet. But the branched
madrepores, which live at consider-
able depth, may form the first
foundation of a reef, and raise a
platform on which other species
may build *, and the sand and

* Joujn, of Geograph, Soc, of London. 1831, p. 218,

'''^'■t.t.f.J'' '

Equatorial Channel

Ch. XVIII.] RATE OF THE GROWTH OF CORAL.

broken fragments washed by the waves from reefs may, in
time, produce calcareous rocks of great thickness.

The rapidity of the growth of coral is by no means great,
according to the report of the natives to Captain Beechey. In
an island west of Gambier's group, our navigators observed
the Chama gigas (Tridacna, Lam.) while the animal was yet
living, so completely overgrown by coral, that a space only of
two inches was left for the extremity of the shell to open and
shut *. But conchologists suppose, that the chama may require
thirty years or more to attain its full size, so that the fact is
quite consistent with a very slow rate of increase in the calca-
reous reefs. In the late expedition to the Pacific no positive
information could be obtained, of any channel having been
filled up within a given period, and it seems established that
several reefs had remained for more than half a century, at
about the same depth from the surface.

The increase of coral limestone, however, may vary greatly
according to the sites of mineral springs, for these we know
often issue in great numbers at the bottom of the sea in vol-
canic regions, as in the Mediterranean, for example, where
they sometimes cause the sea at great depths to be fresher than
at the surface, a phenomenon also declared by the South Sea
islanders to be common in the Pacific.

But when we admit the increase of coral limestone to be
slow, we are merely speaking with relation to the periods of
human observation. It often happens, that parasitic testacea
live and die on the shells of the larger slow-moving gasteropods
in the South Seas, and become entirely inclosed in an incrustation
of compact limestone, while the animal, to whose habitation
they are. attached, crawls about and bears upon his back these
shells, which may be considered as already fossilized. It is,
therefore, probable, that the reefs increase as fast as is com-
patible with the thriving state of the organic beings which
chiefly contribute to their formation ; and if the rate of augmen-
tation thus implied be called, in conformity to our ordinary
ideas of time, gradual and slow, it does not diminish, in the

* Beechey's Voyage to the Pacific, &c. p. 157,

288

ORIGIN OF THE FORM OF

[Ch. XVIII.

least degree, the geological importance of such calcareous
masses.

Suppose the ordinary growth of coral limestone to amount
to six inches in a century, it will then require three thousand
years to produce a reef fifteen feet thick ; but have we any
ground for presuming that, at the end of that period, or of ten
times thirty centuries, there will be a failure in the supply of
lime, or that the polyps and molluscs will cease to act, or that
the hour of the dissolution of our planet will first arrive, as the
earlier geologists were fain to anticipate ?

Instead of contemplating the brief annals of human events,
let us turn to some natural chronometers, to the volcanic isles
of the Pacific, for example, which shoot up ten or fifteen
thousand feet above the level of the ocean. These islands
bear evident marks of having been produced by successive
volcanic eruptions ; and coral reefs are sometimes found on
the volcanic soil, reaching for some distance from the sea-shore
into the interior. When we consider the time required for
the accumulation of such mountain masses of igneous matter
according to the analogy of known volcanic agency, all idea
of extenuating the comparative magnitude of coral limestones,
on the ground of the slowness of the operations of lithogenous
polyps, must instantly vanish.

The information collected during the late expedition to the
Pacific throws much additional light on the peculiarities of
form and structure of coral islands. Of thirty-two of these,
examined by Captain Beechey, the largest was thirty miles in
diameter, and the smallest less than a mile. They were of
various shapes, all formed of living coral, except one, which,
although of coral formation, was raised about eighty feet above
the level of the sea, and encompassed by a reef of living coral.
All were increasing their dimensions by the active operations of
the lithophytes which appeared to be gradually extending and
bringing the immersed parts of their structure to the surface.
Twenty-nine of the number had lagoons in their centres, which
had probably existed in the others, until they were filled, in
the course of time, by zoophytic and other substances.

Ch. XVIII.]

OF CORAL ISLANDS.

2S9

In the above-mentioned islands, the strips of dry coral en-
circling the lagoons when divested of loose sandy materials
heaped upon them, are rarely elevated more than two feet
above the level of the sea ; and were it not for the abrupt
descent of the external margin which causes the sea to break
upon it, these strips would be wholly inundated. " Those parts
of the strip which are beyond the reach of the waves are no
longer inhabited by the animals that reared them, but have
their cells filled with a hard calcareous substance, and present
a brown rugged appearance. The parts which are still im-
mersed, or are dry at low water only, are intersected by small
channels, and are so full of hollows that the tide, as it recedes,
leaves small lakes of water upon them. The width of the
plain or strip of dead coral, in the islands which fell under our
observation, in no instance exceeded half a mile from the usual
wash of the sea to the edge of the lagoon, and in general was
only about three or four hundred yards*." Beyond these
limits the sides of the island descend rapidly, apparently by a
succession of inclined ledges, each terminating in a precipice.
The depth of the lagoons is various ; in some entered by
Captain Beechey, it was from twenty to thirty-eight fathoms.

In the annexed cut (No. 5), one of these circular islands is

View of W Mtsunday Jshmd f .

* Captain Beechey, part i. p. 1S8.
f This plate and the section which follows are copied, hy permission of Cap.
tain Beechey, from the illustrations of his valuable work before alluded to.
Vol. II, tt

290

ORIGIN OF THE FORM

[Ch. XVIII.

represented just rising above the waves, covered with the
cocoa-nut and other trees, and inclosing within, a lagoon of
tranquil water.

The accompanying section will enable the reader to com-
prehend the usual form of such islands. (No. 6.)

No. 6.

Mm h b 4*«

j||iglg»r ~ ~ ----- ~~~ ~ ~ ~~ ~~

Section of a Coral Island.

(a a) Habitable part of the island, consisting of a strip of coral, inclosing the
lagoon. (b b) The lagoon.

The subjoined cut (No. 7) exhibits a small part of the
section of a coral island on a larger scale.

No. 7.

Section of part of a Coral Island,

(a 6) Habitable part of the island.

(6 e) Slope of the side of the island, plunging at an angle of forty-five to the

depth of fifteen hundred feet,
(c c) Part of the lagoon.

(d d) Knolls of coral in the lagoon, with over-hanging masses of coral, re-
sembling the capitals of columns.

The circular or oval forms of the numerous coral isles of
the Pacific, with the lagoons in their centre, naturally suggest
the idea that they are nothing more than the crests of sub-
marine volcanos, having the rims and bottoms of their craters
overgrown by corals. This opinion is strengthened by the
conical form of the submarine mountain, and the steep angle
at which it plunges on all sides into the surrounding ocean.
It is also well known that the Pacific is a great theatre of
volcanic action, and every island yet examined in the wide
region termed Eastern Oceanica, consists either of volcanic
rocks or coral limestones.

It has also been observed that, although within the circular
coral reefs, there is usually nothing discernible but a lagoon,

Ch. XVIII.] OF CORAL ISLANDS. 291

the'bottom of which is covered with coral, yet within some of
these basins, as in Grambier's group, rocks composed of porous
lava and other volcanic substances, rise up, resembling the two
Kameni's, and other eminences of igneous origin, which have
been thrown up within the times of history, in the midst of
the Gulf of Santorin *.

We mentioned that in volcanic archipelagos there is gene-
rally one large habitual vent, and many smaller volcanos
formed at different points and at irregular intervals, all of
which have usually a linear arrangement. Now in several of
the groups of Eastern Oceanica there appears to be a similar
disposition, the great islands, such as Otaheite, Owhyhee,
and Terra del Spirito Santo, being habitual vents, and the
lines of small circular coral isles which are dependent on them
being very probably trains of minor volcanos, which may have
been in eruption singly and at irregular intervals.

The absence of circular groups in the West Indian seas, and
the tropical parts of the Atlantic, where corals are numerous,
has been adduced as an additional argument, inasmuch as
volcanic vents, though existing in those regions, are very in-
ferior in importance to those in the Pacific and Indian seas f .
It may be objected that the circles formed by some coral reefs
or groups of coral islets, varying as they do from ten to thirty
miles and upwards in diameter, are so great as to preclude the
idea of their being volcanic craters. In regard to this objec-
tion we may refer to what we have said in a former volume
respecting the size of the so-called craters of elevation, many
of which, we conceive, may be the ruins of truncated cones

There is yet another phenomenon attending the circular
reefs, to which we have not alluded, viz., the deep narrow
passage which almost invariably leads from the sea into the
lagoon, and is kept open by the efflux of the sea at low tides.
It is sufficient that a reef should rise a few feet above low- water
mark to cause the waters to collect in the lagoon at high tide,

* See vol. i. p. 386.
f Dela Beclie, Geol. Man. p. 141. J See vol. i. p. 388.

U 2

£92 CAUSE OF THE CHANNEL INTO THE LAGOONS. [Ch. XVIII.

and, when the sea falls, to rush out violently at one or more
points where the reef happens to be lowest or weakest. At
first there are probably many openings ; but the growth of the
corals tends to obstruct all those which do not serve as the
principal channels of discharge, so that their number is gra-
dually reduced to a few, and often finally to one. This event
is strictly analogous to that witnessed in our estuaries, where
a body of salt-water accumulated during the flow, issues with
great velocity at the ebb of the tide, and scours out or keeps
open a deep passage through the bar, which is almost always
formed at the mouth of a river.

When we controverted in our first volume Von Buch's theory
of u elevation craters," we suggested that the single gorge lead-
ing from the central cavity to the sea, may have been produced
by a stream of water issuing from a lake filling the original
crater, and which had in process of time cut a deep channel * ;
but we overlooked the more probable cause, the action of the
tides, which affords, we think, a most satisfactory explanation.
Suppose a volcanic cone, having a deep crater, to be at first
submarine, and to be then gradually elevated by earthquakes
in an ocean where tides prevail, a ravine cannot fail to be cut
like that which penetrates into the C aid era of the isle of Palma.
The opening would at first be made on that side where the rim
of the crater was originally lowest, and it would afterwards be
deepened as the island rose, so as always to descend somewhat
lower than the level of the sea. Captain Beechey's observations,
therefore, of the effect of the tides on the coral islands, corro-
borate the opinion which we offered respecting the mode of for-
mation of islands having a configuration like Palma ; whereas
the theory of the sudden upheaving of horizontal strata into
a conical form, affords no explanation whatever of the single
ravine which intersects one side of these circular islands.

In the coral reefs surrounding those volcanic islands in the
Pacific which are large enough to feed small rivers, there is
generally an opening or channel opposite the point where the

* Vol. I, p. 395.

Ch. XVIII.] HEIGHT OF THE WINDWARD SIDE.

293

stream of fresh water enters the sea. The depth of these
channels rarely exceeds twenty-five feet, and they may be
attributed, says Captain Beechey, to the aversion of the litho-
phytes to fresh water, and to the probable absence of the
mineral matter of which they construct their habitations *.

But there is yet another peculiarity of the low coral
islands, the explanation of which is by no means so obvious.
They follow one general rule in having their windward side
higher and more perfect than the other. " At Gambier and
Matilda islands this inequality is very conspicuous, the weather
side of both being wooded, and of the former inhabited, while
the other sides are from twenty to thirty feet under water,
where, however, they might be perceived to be equally narrow
and well defined. It is on the leeward side also that the
entrances into the lagoons occur ; and although they may
sometimes be situated on a side that runs in the direction of
the wind, as at Bow Island, yet there are none to windward."
These observations of Captain Beechey accord perfectly with
those which Captain Horsburgh and other hydrographers have
made in regard to the coral islands of other seas. Thus the
Chagos Isles in the Indian Ocean are chiefly of a horse-shoe
form, the openings being to the north-west ; whereas the pre-
vailing wind blows regularly from the south-east. From this
fortunate circumstance ships can enter and sail out again with
ease, whereas, if the narrow inlets were to windward, vessels
which once entered might not succeed for months in making 1
their way out again. The well-known security of many of
these harbours, depends entirely on this fortunate peculiarity
in their structure.

In what manner is this singular conformation to be ac-
counted for ? The action of the waves is seen to be the cause
of the superior elevation of some reefs on their windward
sides, where sand and large masses of coral rock are thrown
up by the breakers ; but there are a variety of cases where
this cause alone is inadequate to solve the problem ; for reefs
• Voyage to the Pacific, &c., p. 194.

294 HEIGHT OF THE WINDWARD SIDE. [Ch. XVIII.

submerged at considerable depths, where the movements of
the sea cannot exert much power, have, nevertheless, the same
conformation, the leeward being much lower than the wind-
ward side # .

I am informed by Captain King, that on examining the
reefs called Rowley Shoals, which lie off the north-west coast
of Australia, where the east and west monsoons prevail alter-
nately, he found the open side of one crescent-shaped reef, the
Imperieuse, turned to the east, and of another, the Mermaid,
turned to the west ; while a third oval reef, of the same group,
was entirely submerged. This want of conformity is exactly
what we should expect, where the winds vary periodically.

It seems impossible to refer the phenomenon now under
consideration to any original uniformity in the configuration of
submarine volcanos, on the summits of which we may suppose
the coral reefs to grow ; for although it is very common for
craters to be broken down on one side only, we cannot imagine
any cause that should breach them all in the same direction.
But, if we mistake not, the difficulty will be removed if we call
in another part of the volcanic agency — subsidence by earth-
quakes. Suppose the windward barrier to have been raised
by the mechanical action of the waves to the height of two or
three yards above the wall on the leeward side, and then the
whole island to sink down a few fathoms, the appearances
described would then be presented by the submerged reef. A
repetition of such operations by the alternate elevation and
depression of the same mass (an hypothesis strictly conformable
to analogy) might produce still greater inequality in the two
sides, especially as the violent efflux of the tide has probably
a strong tendency to check the accumulation of the more tender
corals on the leeward reef, while the action of the breakers
contributes to raise the windward barrier.

The calcareous formations of the Pacific are probably all
stratified, although single beds may sometimes attain a great
thickness. The occasional drifting of sand from the exposed

* Voyage to the Pacific, &c. ; p. 189.

Ch. XVIII.] STRATIFICATION OF CORAL FORMATIONS.

295

parts of a reef into the lagoon or the surrounding sea, would
suffice to form occasional lines of partition, especially during
violent tempests which occur annually among the South-Sea
islands. The decomposition of felspathic lavas may supply
the current which washes and undermines the cliffs of some
islands with fine clay, and this may be carried to great dis-
tances and deposited in distinct layers between calcareous
masses, or may be mingled with them and form argillaceous
limestones. Other divisions will arise from the arrangement
of different species of testacea and zoophytes, which inhabit
water of various depths, and which succeed each other as the
sea deepens by the fall of the land during earthquakes, or
grows shallower by elevation due to the same cause, or by the
accumulation of organic substances raising the bottom.

To these causes of minor subdivision must be added another
of great importance, — the ejection of volcanic ashes and sand,
often carried by the wind over wide areas, and the flowing of
horizontal sheets of lava, which may interrupt suddenly the
growth of one coral reef, and afterwards serve as a foundation
for another. An example of this kind is seen in the isle of
France, where a bed of coral, ten feet thick, intervenes between
two currents of lava *, and in the West Indies, in the island
of Dominica, Maclure observes that ' f a bed of coral and
madrepore limestone, with shells, lies horizontally on a bed of
cinders, about two or three hundred feet above the level of
the sea, at Rousseau,, and is covered with cinders to a con-
siderable height f."

The reefs in the Pacific are sometimes of great extent : thus
the inhabitants of Disappointment Islands, and those of Duff's
Group, pay visits to each other by passing over long lines of
reefs from island to island, a distance of six hundred miles and
upwards. When on their route they present the appearance
of troops marching upon the surface of the ocean J.

* De la Beche, Geol. Man. p. 142. Quoy and Gaimard, Ann. des Sci. Nat.
tome vi.

I Observations on the Geology of the West Indian Islands, Journal of Science,
&c, No. X'., p. 318. * Malte-Brun's Geog. vol. iii. p. 401.

296 SUBSIDENCE IN EXCESS IN THE PACIFIC. [Ch. XVIII.

A reference to our first volume 1 will show that a series of
ordinary earthquakes might, in the course of a few centuries,
convert such a tract of sea into dry land ; and it is, therefore,
a remarkable circumstance that there should be so immense an
area in eastern Oceanica, studded with minute islands, without
one single spot where there is a wider extent of land than be-
longs to such islands as Otaheite, Owhyhee, and a few others,
which either have been or are still the seats of active volcanos.
If an equilibrium only were maintained between the upheaving
and depressing force of earthquakes, large islands would very
soon be formed in the Pacific ; for, in that case, the growth of
limestone, the flowing of lava, and the ejection of volcanic
ashes, would combine with the upheaving force to form new
land.

Suppose the shoal which we have described as six hundred
miles in length, to sink fifteen feet, and then to remain un-
moved for a thousand years ; during that interval the grow-
ing coral may again approach the surface. Then let the
mass be re-elevated fifteen feet, so that the original reef is
restored to its former position : in this case the new coral
formed since the first subsidence, will constitute an island
six hundred miles long. An analogous result would have
occurred if a lava-current fifteen feet thick had overflowed the
submerged reef. The absence, therefore, of more extensive
tracts of land in the Pacific seems to show that the amount of
subsidence by earthquakes exceeds in that quarter of the
globe at present the elevation due to the same cause.

We mentioned that one of the thirty-two islands examined
by our navigators in the late expedition, was raised about
eighty feet above the level of the sea*. It is called Elizabeth
or Henderson's Island, and is five miles in length by one
in breadth. It has a flat surface, and on all sides except the
north, is bounded by perpendicular cliffs about fifty feet high,
composed entirely of dead coral, more or less porous, honey-
combed at the surface, and hardening into a compact calcareous
* According to some accounts between sixty and seventy feet.

Ch. XVIII.] ELIZABETH OR HENDEKSON's ISLAND. 297

mass, which possesses the fracture of secondary limestone, and
has a species of millepore interspersed through it. These
cliff's are considerably undermined by the action of the waves,

No. 8.

Enlarged vieio of part of Elizabeth or Henderson's Island.

and some of them appear on the eve of precipitating their
superincumbent weight into the sea. Those which are less
injured in this way present no alternate ridges or indication
of the different levels which the sea might have occupied at
different periods, but a smooth surface, as if the island, which
has probably been raised by volcanic agency, had been forced
up by one great subterraneous convulsion *.

At the distance of a few hundred yards from this island, no
bottom could be gained with two hundred fathoms of line.
It will be seen from the annexed sketch, communicated to me
by Lieutenant Smyth, of the Blossom, that the trees come
down to the beach towards the centre of the isle, a break which
at first sight resembles the openings which usually lead into
lagoons : but the trees stand on a steep slope and no hollow of
an ancient lagoon was perceived. The reader will remark
that such a mass of limestone represents exactly those hori-
zontal cappings of calcareous strata which we sometimes find,
on hills which have tabular summits.

As we have at present no proof that Henderson's Island has
been upheaved within the historical period, we deviate some-
what from our plan when we describe it in the present chapter;
but, as earthquakes are now felt from time to time in this part
of the Pacific, and as indications of very recent changes of level

* Beechey, ib. p. 46.

298

EXTENT OF CORAL FORMATIONS.

[Ch. XVIII.

are not wanting*, it is by no means improbable that the era
of the elevation of this island may not be very remote.

The calcareous masses which we have now- considered, con-
stitute, together with the associated volcanic formations, the
most extensive of the groups of rocks which can be demon-
strated to be now in progress. The space in the sea which
they occupy is so vast, that we may safely infer that they ex-
ceed in area any group of ancient rocks which can be proved
to have been of contemporaneous origin. We grant that each
of the great archipelagos of the Pacific are separated by un-
fathomable abysses, where no zoophytes may live and no lavas
flow, where not even a particle of coral sand or volcanic scorise
may be drifted : we confine our view to the extent of reef ascer-
tained to exist, and assume that a certain space around each
volcanic or coral isle has been covered with ejections or matter
from the waste of cliffs, and it will then be seen that the space
pccupied by these formations may equal, and perhaps exceed
in area that part of our continents which has been accurately
explored by the geologist.

That the increase of these calcareous masses should be
principally, if not entirely, confined to the shallower parts of
the ocean, or, in other words, to the summits of submarine
ranges of mountains and elevated platforms, is a circumstance
of the highest interest to the geologist ; for, if parts of the
bed of such an ocean should be upraised, so as to form large
continents, mountain-chains might appear, capped and flanked
by calcareous strata of great thickness, and replete with organic
remains, while in the intervening lower regions no rocks of
contemporary origin would ever have existed.

A modern writer has attempted to revive the theory of some
of the earlier geologists, that all limestones have originated in
organized substances. If we examine, he says, the quantity
of limestone in the primary strata, it will be found to bear a
much smaller proportion to the siliceous and argillaceous rocks
than in the secondary, and this may have some connexion with
* See Captain Beechey's Voyage to the Pacific, &c., pp. 159 and 191.

Ch. XVIII.] ANIMAL ORIGIN OF LIMESTONE CONSIDERED. 299

the rarity of testaceous animals in the ancient ocean. He
farther infers that in consequence of the operations of animals,
" the quantity of calcareous earth deposited in the form of
mud or stone is always increasing ; and that as the secondary
series far exceeds the primary in this respect, so a third series
may hereafter arise from the depths of the sea, which may
exceed the last in the proportion of its calcareous strata*."

If these propositions went no farther than to suggest that
every particle of lime that now enters into the crust of the
globe, may possibly in its turn have been subservient to the
purposes of life by entering into the composition of organized
bodies, we should not deem the speculation improbable; but
when it is hinted that lime may be an animal product com-
bined by the powers of vitality from some simple elements, we
can discover no sufficient grounds for such an hypothesis, and
many facts which militate against it.

If a large pond be made, in almost any soil, and filled with
rain water, it may usually become tenanted by testacea, for
carbonate of lime is almost universally diffused in small quan-
tities. But if no calcareous matter be supplied by waters flow-
ing from the surrounding high grounds or by springs, no tufa
or shell-marl are formed. The thin shells of one generation of
molluscs decompose, so that their elements afford nutriment to
the succeeding races ; and it is only where a stream enters a
lake, which may introduce a fresh supply of calcareous matter,
or where the lake is fed by springs, that shells accumulate and
form marl.

All the lakes in Forfarshire which have produced deposits
of shell-marl, have been the sites of springs which still evolve
much carbonic acid, and a small quantity of carbonate of lime.
But there is no marl in Loch Fithie, near Forfar, where there
are no springs, although that lake is surrounded by these cal-
careous deposits, and although, in every other respect, the site
is favourable to the accumulation of aquatic testacea.

We find those charas which secrete the largest quantity of
* Macculloeh's Syst. of Geol., vol. i, p. 219.

300 THE THEORY THAT CALCAREOUS MATTER [Qi. XVIII.

calcareous matter in their sterns^ to abound near springs im-
pregnated with carbonate of lime. We know that if the com-
mon hen be deprived altogether* of calcareous nutriment, the
shells of her eggs will become of too slight a consistency to
protect the contents, and some birds eat chalk greedily during
the breeding season.

If on the other hand we turn to the phenomena of inorganic
nature, we observe that, in volcanic countries, there is an enor-
mous evolution of carbonic acid, mixed with water or in a
gaseous form, and that the springs of such districts are usually
impregnated with carbonate of lime in great abundance. No
one who has travelled in Tuscany, through the region of ex-
tinct volcanos and its confines, or who has seen the map recently
constructed by Targioni to show the principal sites of mineral
springs, can doubt for a moment, that, if this territory was sub-
merged beneath the sea, it might supply materials for the most
extensive coral reefs. The importance of these springs is not
to be estimated by the magnitude of the rocks which they
have thrown down on the slanting sides of hills, although of
these alone large cities might be built, nor by a coating of
travertin that covers the soil in some districts for miles in
length. The greater part of the calcareous matter passes down
in a state of solution to the sea ; and a geologist might as well
assume the mass of alluvium formed in a few years in the
bed of the Po, or the Ganges, to be the measure of the quantity
deposited in the course of centuries in the deltas of those rivers,
as conceive that the influence of the carbonated springs in Italy
can be estimated by the mass of tufa precipitated by them
near their sources.

It is generally admitted that the abundance of carbonate of
lime given out by springs, in regions where volcanic eruptions
or earthquakes prevail, is referrible to the solvent power of
carbonic acid. For, as the acidulous waters percolate calcareous
strata, they take up a certain portion of lime and carry it up
to the surface where, under diminished pressure in the atmo-
sphere, it may be deposited, or, being absorbed by animals and

Ch. XVIII.] IS ON THE INCREASE CONTROVERTED.

301

vegetables, may be secreted by them. In Auvergne, springs
charged with carbonate of lime rise through granite, in which
case we must suppose- the calcareous matter to be derived from
some primary rock, unless we imagine it to rise up from the
volcanic foci themselves.

We see no reason for supposing that the lime now on the
surface, or in the crust of the earth, may not, as well as the
silex, alumine, or any other mineral substance, have existed
before the first organic beings were created, if it be assumed
that the arrangement of the inorganic materials of our planet
preceded in the order of time the introduction of the first
organic inhabitants.

But if the carbonate of lime secreted by the testacea and
corals of the Pacific, be chiefly derived from below, and if it be
a very general effect of the action of subterranean heat to sub-
tract calcareous matter from the inferior rocks, and to cause it
to ascend to the surface, no argument can be derived in favour
of the progressive increase of limestone from the magnitude of
coral reefs, or the greater proportion of calcareous strata, in
the more modern formations. A constant transfer of car-
bonate of lime from the inferior parts of the earth's crust to its
surface, would cause throughout all future time, and for an
indefinite succession of geological epochs, a preponderance of
calcareous matter in the newer, as contrasted with the older
formations.

DESCRIPTION OF THE PLATES AND MAP.

FRONTISPIECE.

View of part of the Valley del Bove, on the East side of
the great Cone of Etna.

This valley is a cavity of immense depth, commencing at a
short distance below the summit of Etna, and descending
through that zone of the mountain where lateral eruptions
are frequent. The general dip of the volcanic beds in the
precipices surrounding this valley is towards the sea, but ex-
ceptions occur where lateral cones have been buried in the
manner described in the first volume (p. 363). The stu-
pendous precipices surrounding this great amphitheatre vary
from 600 to nearly 3000 feet in height, and they are traversed
on all sides by innumerable vertical walls or dikes of compact
lava, which cut through the sloping beds of lava, sand, and
scorise, of which the great cone is formed. These dikes,
which will be described in the next volume, seem all to have
been produced by ancient lateral eruptions on the flanks of
Etna.

The causes which have produced this great depression in
the otherwise symmetrical cone of the volcano will be discussed
in the third volume, and we shall merely state here, that we
consider the conformation of the rocky barrier encircling the
cavity, as entirely at variance with an hypothesis recently
proposed, that the hollow was a crater of eruption from
whence the scorise of the surrounding heights have proceeded.

We have introduced two colours into the plate, the grey to
express that part of the mountain which may have been formed
before the origin of the " Val del Bove/' the red to indicate
the part which has resulted from eruptions subsequent to the

304

DESCRIPTION OF THE PLATES AND MAP.

formation of the valley. The great lava currents of 1819
and 1811, described in the first volume (p. 367), are seen
pouring down from the higher parts of the valley, overrunning
the forests of the great plain, and rising up in the foreground
on the left with a rugged surface, on which small hillocks and
depressions are seen, such as often characterize a lava-current
immediately after its consolidation.

The small cone, No. 7, was formed in 1811, and was still
smoking when I saw it in 1828. Immediately in front of it
is seen another cone, formed during the same eruption. The
other small volcano to the left, from which vapour is issuing,
was formed, I believe, in 1819.

This sketch, which forms part of a panoramic drawing which
I made in November 1828, is merely intended to assist the
reader, in comprehending some geological details into which
we shall hereafter enter, on the structure of the older portion
of Etna, but it will give no idea of the extraordinary geolo-
gical interest, still less of the picturesque grandeur of this
magnificent scene of desolation. Nor is the view sufficiently
extensive to exhibit the entire form of the vast amphitheatre,
part only of the northern, and scarcely any of the southern
boundary of which is included.

MAP

Shewing the extent of Surface in Europe which has been
covered by Water since the Deposition of the older Tertiary
Strata. (Strata of the Paris and London Basins, Sfc.)

[Constructed chiefly from M. AmieBoue's Geological Map of Europe.]

This map will enable the reader to perceive at a glance
the great extent of change in the physical geography of
Europe, which can be proved to have taken place since some
of the older tertiary strata were deposited. The most ancient
part of the period to which the map refers cannot be deemed

DESCRIPTION OF THE PLATES AND MAP.

805

very remote, considered geologically, because the deposits of
the Paris and London basins, of Auvergne, and many other
districts belonging to the older tertiary epoch, are newer than
the greater part of the sedimentary rocks of which the crust of
the globe is composed. The species, moreover, of marine and
fresh-water testacea, of which the remains are found in these
formations, are not entirely distinct from such as now live ; a
proportion of about three in a hundred of the fossil species
having been identified with species now living. Yet, not-
withstanding the comparatively recent epoch to which the
retrospect is carried, the variations in the distribution of land
and sea depicted on the map, form only a part of those which
must have taken place during the period under consideration.
Some approximation has merely been made to a correct estimate
of the amount of sea converted into land in that part of Europe
best known to geologists, but we cannot determine how much
land has become sea during the same period ; and there may
have been repeated interchanges of land and water in the same
places, mutations of which no account is taken in the map, and
respecting the amount of which little accurate information can
ever be obtained by geologists.

The proofs of submergence, during some part of the ter-
tiary period, throughout the districts distinguished by ruled
lines, are of a most unequivocal character ; for the area thus
described is now covered by deposits, containing the remains of
aquatic animals belonging to tertiary species. We have, indeed,
extended the sea in two or three instances beyond these limits,
because other geological data have been obtained for inferring
the submergence of these tracts subsequently to the com-
mencement of the deposition of the tertiary strata. Thus we
shall explain, in the next volume, our reasons for concluding
that part of the chalk of England, (the north and south downs,
for example, together with some other adjoining secondary
tracts,) continued beneath the sea until the older tertiary beds
had begun to accumulate.

It is possible also that a considerable part of Caernarvon-

Vol. II. X

306

DESCRIPTION OF THE PLATES AND MAP.

shire might with propriety have been represented as sea, if
our information respecting the geology of that country had
been more full and accurate ; for marine shells have been found
in sand and gravel at the height of one thousand feet above
the level of the sea, on the summit of Moel Tryfane, between
Snowdon and the Menai Straits. The species are apparently
recent, but certainly are newer than the older tertiary epoch *.

The introduction of a small bay where the river Ribble
enters into the sea in Lancashire, is warranted by the newly
discovered deposit of tertiary shells covering an area of about
thirty miles square in that region f .

A portion also of the primary district in Brittany is divided
into islands, because it has been long known to be covered with
patches of marine tertiary strata ; and when I examined the
disposition of these, in company with my friend Captain S. E.
Cook, H.N., in 1830, I was convinced that the sea must have
covered much larger areas than are now occupied by these
small and detached deposits.

The former connexion of the White Sea and the Gulf of
Finland is proved by the fact that a broad band of tertiary
strata extends throughout part of the intervening space. We
have represented the channel as somewhat broader than the
tract now occupied by the tertiary formation, because the latter
is bordered on the north-west by a part of Finland, which is
extremely low, and so thickly interspersed with lakes as to be
nearly half covered with fresh- water.

Certain portions of the north-western shores of Norway
have been left blank, because the discovery by Von Buch,
Brongniart, and others, of deposits of recent shells along the
coast of Norway and Sweden, at several places and at various
heights above the level of the sea, attest the comparatively

* Joshua Trimmer, Esq., Proceedings of the Geological Society of London,
No. 22, 1831. The shells were exhibited at the Geological Society when the
memoir was read.

f See an abstract of a memoir read by Mr. Murchison, Pres. Geol. Soc, Pro-
ceedings of York meeting, 1831.

DESCRIPTION OF THE PLATES AND MAP.

307

recent date of the elevation of part of the gneiss and other
primary rocks in that country, although we are unable as yet
to determine how far the sea may have extended.

On the other hand, a considerable space of low land along
the shores of the Gulf of Bothnia, in the Baltic, is represented
as sea, because the growth of deltas on that coast, and the
shallowing of the water by sedimentary deposits during the
historical era, leave no room for doubt that the extent of the
gulf must have been very much greater at some periods since
the older tertiary epoch.

The low granitic steppe coloured red, to the north of the
Black Sea has not been represented as having been under
water during the tertiary period, although, from the quantity
of marine tertiary strata in the surrounding districts, it is far
from improbable that it has recently emerged.

We were anxious, in the observations annexed to the title of
this map, to guard the reader against the supposition that it
was intended to represent the state of the physical geography
of part of Europe at any one period. It is not a restoration
of a former condition of things, but a view of the change which
a certain amount of surface has undergone within a given
period, an alteration so complete, that not one of the species of
organic beings which now inhabit the large space designated
by ruled lines, beyond the borders of the existing seas, can
have lived there during some other period subsequent to the
commencement of the tertiary era.

We have stated, in the first volume *, that the movements of
earthquakes occasion the subsidence as well as the upraising of
the surface ; and that, by the alternate rising and sinking of
particular spaces, at successive periods, a great area may have
been entirely covered with marine deposits, although the
whole may never have been beneath the waters at one time ;
nay, even though the relative proportion of land and sea may
have continued unaltered throughout the whole period. We
believe, however, that since the commencement of the tertiary

* Page 126.

X 2

308

DESCRIPTION OF THE PLATES AND MAP.

period, the dry land in the northern hemisphere has been con-
tinually on the increase, not only because it is now greatly in
excess beyond the average proportion which land generally
bears to water on the globe, but because the comparison of the
secondary and tertiary strata implies a passage throughout the
space now occupied by Europe, from the condition of an ocean
interspersed with islands to that of a large continent.

But if it were possible to represent all the vicissitudes in the
distribution of land, and sea that have occurred during the
tertiary period, and to exhibit not only the actual existence of
land where there was once sea, but also the extent of surface
now submerged, which may once have been land, the map
would still fail to express all the important revolutions in
physical geography, which have taken place within the epoch
under consideration. The oscillations of level have not merely
been such as to lift up the land from below the waters to a
small height above them, but in some cases a rise of several
thousand feet has been effected. Thus the Alps have ac-
quired an additional altitude of from 2000 to 4000 feet, and
even in some places still more; and the Apennines owe a
great part of their height (from 1000 to 2000 feet and
upwards) to subterranean convulsions which have happened
within the tertiary epoch.

On the other hand, some mountain chains may have been
loAvered, during the same series of ages, in an equal degree,
and shoals may have been converted into deep abysses.

It would be superfluous to point out in detail the bearing
of the facts exhibited in this map, on the theories proposed in
a former part of this volume, respecting the migrations of
animals and plants, and the extinction of species; and it
would be equally unnecessary to enlarge on the variations in
local climate, which must have accompanied such vicissitudes
in physical geography.

But the general temperature, also, of the habitable surface
of the globe, as well as the local climates, may have been con-
siderably modified by such extraordinary revolutions. The

DESCRIPTION OF THE PLATES AND MAP.

309

alteration in climate, implied by a comparison of the organic
remains of the older tertiary strata, and the species of living
animals and plants, does not appear to be so great as would be
produced if the temperature of our tropics were now trans-
ferred to the temperate zone, and the temperature of the latter
to the arctic. We do not, therefore, anticipate that the reader,
who has duly studied the arguments explained by us in the
6th, 7th, and 8th chapters of the first volume, will object to
the adequacy of the cause proposed, on the score of the small
quantity of geographical change during the time in question.

But if there be good reason to conclude that the change
would be fully adequate, in point of the magnitude of its effects,
this cause, we conceive, ought to supersede every other of a
purely speculative nature, until some argument can be adduced
to prove that the change has not acted in the right direction *.

Some persons, but slightly acquainted with the present state
of geology, have objected, that the lands in high northern
latitudes have not been recently elevated. If they had re-
flected that every year we are making some new discoveries
respecting the periods when tracts in the immediate neigh-
bourhood of the great European capitals emerged from the
deep, and had they sufficiently considered that the antiquity
of a group of rocks has no necessary connexion with the date
of its elevation, they would probably have seen the futility of
such arguments. As far as we can conjecture, from the very
scanty information which we possess of the geology of the
arctic region, there is no want of proofs of comparatively
recent alterations of level.

In conclusion, we may remark that the portion of Europe
distinguished in this map by colours and ruled lines, com-
prises the greater part of the globe now known to geologists —
almost all at least that is known in such a manner as to en-
title any one to speculate on the mutations in physical geo-
graphy which have taken place during the tertiary period.

* See Mr. Herschell's remarks on a change of climate Disc, on the Study

of Nat. Phil., pp. 146 and 148.

310

DESCRIPTION OF THE PLATES AND MAP.

In regard to other parts of the 'world, we have no reason for
inferring, from any data hitherto obtained, that during an
equal lapse of the ages which immediately preceded our times,
an equal amount of alteration of surface may not have taken
place.

LIST OF WOOD-CUTS.

It Eggs of fresh- water Molluscs, p. 111.

2. Seed-vessel of Chara hispida, p. 273.

3. Stem and branches of ditto, p. 274.

4. Chain of coral islets, called theMaldivas, p. 286.

5. View of Whitsunday Island, p. 289.

6. Section of a coral island, p. 290.

7. Ditto of part of a coral island, p. 290.

8. Elizabeth, or Henderson's Island, p. 297.

9. Enlarged view of part of ditto, p. 297.

INDEX.

Vol. II.

AcatriRED habits of animals rarely

transmissible, page 48.
Adige, its delta increased by the system

of embankment, 203.
iElian, on the breeding of elephants in

captivity, 40.
Africa, devastations caused by locusts

in, 137.

many species probably annihilated

by the advance of the sands of, 166'.

dried carcasses of camels imbedded

in the deserts of, 235.

■ strata now forming off the coast

of, 282.

African desert, its area as compared to

the Mediterranean, 166.
Airthrey, a fossil whale found at, 279.
Alga, great depths at which some

species live, 72.
may leave traces of their form in

calcareous mud, 278.
Alloa, whale cast ashore at, 278.

fossil whale found near, 279.

Alluvium, stalagmite found alternating

with in French caves, 222.

i imbedding of organic remains

in, 228.

Alps, have been greatly raised during
the tertiary epoch, 308.

Alternations of marine and fresh-water
strata, how formed, 277-

America, specific distinctness of the ani-
mals in, and those of the Old World,
66, 87.

i domesticated animals have run
wild in, 28, 153.

rapid multiplication of domestic

quadrupeds in, 152.

— — number of plants common to the
Old World, and, 69.

■ number of square miles of useful

soil in, 155.

Andes, may have undergone great
changes of level in the last 6000
years, 265.

■ effects which it is said would re-
sult from their sudden elevation, 279

Animal kingdom, theory of the unin-
terrupted succession in the, 2.

Animal origin of limestone theory con-
sidered, 298.

Animal remains in caves and fissures
219.

Animals, Lamarck's theory of the pro-
duction of new organs in, 7-

imported into America have run

wild, 28.

aptitude of some kinds to domes-
tication, 38.

hereditary instincts of, 39.

domestic qualities soon developed

in some, 47-

some of their qualities given with

a view to their connexion with man^
41, 44, 47.

their acquired habits rarely trans-
missible, 48.

i changes in the brain of the foetus

in vertebrated, 62.

their agency in diffusing plants, 78.

their geographical distribution, 87-

different regions of indigenous, 88.

in islands, 90.

their powers of swimming, 92.

migrations of, 94.

their power of crossing the sea

very limited, 96.

causes which determine the sta-
tions of, 130, 140.

■ influence of society in altering the

distribution of, 149.

migratory powers indispensable

to, 159.

manner in which they become

preserved in peat, 216.
remains of those most common in

peat mosses, 21 8.
most abundantly preserved where

earthquakes prevail, 230.
— — imbedded by floods in Scotland, 230.
imbedded by river inundations,

247-

found imbedded in Scotch marl

lakes, 251 .

Animate creation, changes now in pro-
gress in the, 1 .

Antagonist powers, synchronism of their
action, 196.

Antiseptic property of peat, whence de-
rived, 216.

Ants, their ravages in Grenada, 137.

312

INDEX.

Apennines, have been a vegetable centre
whence species diffused tkemselves,178.

in great part elevated during the

tertiary epoch, 308.

Aphides, White's account of a shower
of, 114.

— — their rapid multiplication, 135.

ravages caused by, ] 36.

Aphonin, on the diffusion of man over

the globe, 117-
Apure, river, wild horses drowned in

great numbers by the annual floods of

the, 249.

Aquatic and terrestrial species, their re-
ciprocal influence, 138.

Aquatic species, imbedding of their re-
mains in subaqueous strata, 272.

Aqueous lavas in Campania, seven per-
sons destroyed by, 236.

Arabian Gulf, rapidly filling with coral,
285.

Arctic region, on alterations of level in
the, 309.

Ass, the, has run wild in Quito, 153.

■ wild, account of their migrations
in Tartary, 95.

Astrea, genus, instrumental in the for-
mation of coral, 284.

Athabasca Lake, large shoal formed by
drift-wood in, 242.

Atlantic, absence of circular coral groups
in the, 291.

Aubenas, fissures filled with breccia
near, 220.

Augustin, St., on a plague caused by
locusts in Africa, 137-

Australia, the kangaroo and emu giv-
ing way in, 150.

■ vegetation of, 178.

extent of coral reefs off the coast

of, 285.

Auvergne, tertiary deposits of, 304.

Baboon of Sumatra, trained to ascend
trees, 47.

Bacon, Lord, on the vicissitudes of

things, 271.
Baffin's Bay, marine animals found at

great depths in, 181.
Bakewell, Mr., on the formation of

soils, 188.

■ his account of the fall of Mount

Grenier, 229.
Bakie loch, chara found in a fossil state

in, 274.

Ballard, M., on changes which some
human bones have undergone, in
fourteen or fifteen centuries, 225.

Banks formed by drift sea-weed, 277.

Barbadoes, rain diminished by the fell-
ing of forests in, 200.

Barriers to the distribution of species,
remarks on, 172.

Barrow, Mr., Lis account of a bank
formed in the sea by the bodies of
locusts, 138.

Barton, Mr., on the agency of insects in
the fructification of plants, 54.

■ on the geography of plants, 67-

Baumhauer, Mr., his account of a vio-
lent river-flood in Java, 250.

Bears, once numerous in Wales, 149.

black, migrate in great numbers, 94.

Beaver, once an inhabitant of Scotland
and Wales, 149.

remains of the, found in shell-
marl, in Perthshire, 251.

Bee, number of instincts of the, 58.

Beechey, Captain, on the drifting of
canoes in the Pacific, 120.

on the buried temple of Ipsambul,

234.

on the rate of the growth of coral

in the Pacific, 287.
■ on the situation of the channels

into the lagoons of coral islands, 293.
on the superior height of the

windward side of coral islands, 293.
his description of Elizabeth or

Henderson's Island, 297.
on recent changes of level in the

Pacific, 298.
Belcher, Captain, on the strata now

forming in the sea off the coast of

Africa, 282.
Belzoni, on the buried temple of Ipsam-

bul, 234.

his account of a flood on the Nile,

253.

Berkely, on the recent origin of man,
270.

Bewick, on the great geographical range
of some birds, 101.

on the distribution of the bustard

in England, 150.

Bhooi, volcanic eruption at, during
Cutch earthquake, 238.

Bigsby, Dr., on the North American
lakes, 275.

Birds, diffusion of plants by, 80.

geographical distribution of, 100.

1 some species very local, 100.

• their powers of diffusion, 101.

periodical migrations of, 101.

great range of some species, 101.

■ rate of the flight of, 102.

frequently overtaken by hurri-
canes, 102.

their agency in the distribution of

fish, 106.

' many species of, unremittingly

persecuted, 149.

INDEX.

313

Birds, recent extermination of some

species of, 150.

bones of in Gibraltar breccia, 223.

' rarity of their remains in new

strata, 246.
Bisons, immense herds of, in the Mis-
sissippi valley, 93.
Bize, human remains found mixed with

extinct mammalia in a cave at, 224.
Black cattle, their rapid multiplication

in South America, 152.
Black Sea, marine tertiary strata found

near the, 307-
Blavier, M., on the peat at the mouth

of the Loire, 211.
Bloomfield, bursting of a peat moss

near, 218.

Blown sand, imbedding of organic re-
mains, &c. in, 234.

Boa constrictor, account of one con-
veyed to St. Vincent's on drift-wood,
104.

Boates, Dr., on Irish peat-hogs, 211.
Boblaye, M., on the formation termed

ceramique, in the Morea, 233.
Bog iron ore, whence derived, 214.
Bonaparte, C, on the birds common to

Rome and Philadelphia, 101.
Bonelli, Professor, on the migrations of

the painted lady butterfly, 113.
Bonpland, on the plants common to the

old and new world, 69.
Bordeaux, timber destroyed by a beetle

introduced by commerce at, 122.
Borneo, the orang-outang taught to

ascend trees by the inhabitants of, 47-
Boston, a narwal found buried in mud

on the beach near, 278.
Botanical geography, 67-
Botanical provinces, their number, 71.

1 how caused, 125.

■ ■ why not more blended together, 127-

Bothnia, gulf of, its extent formerly

much greater, 307-
Boyne, a large whale stranded at, 278.
Brand, Rev. J. F., on the birth-place of

man, 117-
British vessels, average numher wrecked

annually, 254, 257.
durable nature of many of their

contents, 256, 257-
British coasts, cetacea frequently strand-
ed on the, 278.
Brittany, a village in, buried under

blown sand, 235.

■ marine tertiary strata of, 305.

Brocchi, his remarks on the extinction

of species, 128.
Broderip, Mr., on the agency of lan-

thina fragilis, in disseminating other

species, 108.

Broderip, Mr., some large bulimi re-
stored to life after twenty months'
abstinence, by, 1 09.

Bromberg, a vessel and two anchors dug
up near, 260.

Brongniart, M., his discovery of recent
shells at considerable heights in
Sweden, 306.

Brown, Mr., on the plants common to
Africa, Guiana, and Brazil, 16.

on the vegetation of New Holland,

178.

Buckland, Dr., on animal remains in

caves, 219.
on the remains of recent quadru-
peds in fissures, 220.

on stalagmite of caves, 222.

on human remains in caves, 223.

■ on the organic remains in the cave

of Paviland, 223.
Buffaloes destroyed in great numbers

by a river flood in Java, 250.
Butfon, on the want of specific identity

in the animals of the Old and New

World, 66.
— — ■ on the geographical distribution of

animals, 87.
on the check which the increase of

one animal offers to that of another,

154.

his remarks on the gradual ex-
tinction of species, 176.
Buildings submerged without being

thrown down, examples of, 266, 269.
Bura and Helice, submerged Grecian

towns, 269.
Burckhardt, buried temple of Ipsam-

bul, discovered by, 234.
1 his account of the carcasses of

camels in the Libyan sands, 235.
Burnes, Lieut. A., his account of the

effects of the earthquake of Cutch,

1819,266.
Burnt island, whale cast ashore near, 278.
Burrampooter, bodies of men, deer, &c.,

conveyed to the sea by the floods of

the, 250.

Burringdon, human remains found in a
cave at, 223.

Burrowing shells secure from the ordi-
nary action of the waves, 280.

Bustards recently extirpated in Eng-
land, 150.

Bywell, bodies washed out of the
churchyard of, by floods, 254. ,

Cabbages, examples of deviation from
a common type shown in different
races of, 33.',

Cachalots, a herd of stranded at Kair-
ston, in Orkney, 278.

314

INDEX.

Caernarvonshire, recent discovery of
tertiary strata in, 305.

Calabria, animals how preserved in al-
luvium in, 230.

animals engulphed in fissures in,

231.

Calcareous marl of the Scotch lakes,

shells found in the, 272.
Calcareous formations of tlie Pacific,

probably all stratified, 294.

■ their great extent, 298.

Calcareous matter, the theory that it is

on the increase controverted, 300.
Caldera of the isle of Palma, ravine in

the, how formed, 292.
Callao, recent changes of level caused by

earthquakes in, 265.
Camels, the carcasses of imbedded in

drift-sand, 235.
Campania, people destroyed by aqueous

lavas in, 236.
Campbell, Mr.," on the migration of

quaggas in South Africa, 95.
Camper, on the gradation in intellect as

shown by the facial angle, 60.
Cannon inclosed in calcareous rock

taken up from the delta of the Rhone,

262.

— ■ account of one taken up near the

Downs, 262.
Canoes full of men and women drifted

to great distances, 119.
eight found in draining Martin

Meer, Lancashire, 260.

several found in Loch Doon, 261.

Cape Langaness, drift-wood abundant

at, 244.

Carcasses of camels in drift-sand, 235.
Caryophvllia, coral formed by the genus,
284.

Caspian, on the level of the, 163.

Caspian and Black Sea formerly con-

*~ nected by straits, 100.

Castle, Mr., on the ravages of ants in
Grenada, 137-

Catalonia, devastation caused by tor-
rents in, 199.

Catania, part of the town of overflowed
by lava, 236.

■ tools discovered in digging a well

at, 259.

Catastrophes, remarks on general, 161.

Caterpillars, ravages caused by some
kinds, 136.

Catodon, Hay's account of a large one
stranded in Holland, 278.

a herd of them stranded in Ork-
ney, 278.

Caverns, organic remains in, may, in
some cases, have fallen through fis-
sures, 221.

Caves, organic remains in, 219.

preserved by sediment introduced

by land-floods, 221.
■ alternations of sediment and sta-
lagmite in some, 222.
Dr. Buckland on human remains

in, 223, 227.
• marine and terrestrial shells of

eatable species found in, 224.
Cayes, works of art found at a depth of

twenty feet at, 259.
Central India, buried cities in, 237.
Cerarnique, account of the formation

termed, 233.
Cetacea, their geographical range, 91.

migrations of the, 99.

identity of those found in the

Mediterranean and Caspian Seas, 99.
imbedding' of their remains in

recent strata, 278.
often stranded on low shores

during storms, 278.
. their remains should be more fre-
quent in marine alluvium than those

of land quadrupeds, 279.
Chagos isles, their linear direction, 286.
■ openings into them in the opposite

direction to the prevailing wind, 293.
Chalk of the north and south downs

elevated after the commencement of

the tertiary era, 305.
Chama gigas, time which it requires to

attain its full growth, 287.
■ found in the Pacific completely

overgrown by coral, 287.
Chamisso, M., on the formation of coral

islands, 284.
Channel into the lagoons of coral

islands, how formed, 292.
Chara hispida, its structure described,

see wood-cuts, No. 2 and 3, 273, 2?4.
Chara?, fossilized in the lakes of Forfar-
shire, 273.
Chockier, three alterations of stalagmite

and alluvium in a cave at, 222.
Christol, M. de, on human remains, &c.

in caves, with extinct quadrupeds,

224.

Climate, its influence on the distribu-
tion of plants, 68.

effect of alterations in, on the dis-
tribution of species, 169.

its influence in causing one species

to give way before another, 172.

. influence of vegetation on, 200.

on the alteration which changes in

physical geography may have caused
in, 308.

Coal, formation of, at the mouths of the

Mackenzie, 242.
Coiron, land shells in breccia at, 220.

INDEX.

315

Colebrooke, Major R. XL, on the forma-
tion of new islands in the Ganges, 203.

Columella, on the breeding of elephants
in captivity, 46.

Conception, changes of level caused by
earthquakes at, 2C5.

Cones formed on Etna in 1810 and
1811 (see frontispiece) , 304.

Conservative influence of vegetation,
198.

Cook, Captain, on the diffusion of nut-
meg seeds by pigeons, 80.

on the drifting of canoes to great

distances, 119.

Cook, Captain S. E., examined Brittany
with the author, 306. *

Coral, rate of the growth of, in the
Pacific, 287.

its growth probably varies accord-
ing to the sites of mineral springs,287-

1 found between two lava currents

in the West Indies, 294.

Coral animals, their action compared to
plants which generate peat, 283.

i MM. Quoy and Guimard on the

depth at which they live, 286.

Coral islands, formation of, 284.

linear direction of, see wood-cut

No. 4, 286.

origin of the form of, 288.

» two sections explaining their form,

see diagrams Nos. 6 and 7, 290.

many probably the crests of sub-
marine volcanos. 290.

their windward side higher and

more perfect than the other, 293.

Coral reefs, formation of, 283.

■ great beds of oysters, &c, found

on, in the Pacific, 283.

genera of zoophytes by which they

are constructed, 284.

their extent, 285, 295, 298.

linear direction of, 286.

rapidity of the growth of, 287-

the most extensive formation now

in progress, 298.

Cornwall, ruins of buildings found in
the drift-sand of, 235.

Corse, Mr., on the habits, &c. of the ele-
phant, 46.

Cowslip, Linna3iis on the varieties of
the, 34.

Crantz, on the drift-wood of the North
Sea, 244,

Creation, supposed centres, or foci, of
126.

Crocodile taken in the Rhone, 104.

Crocodiles imbedded by a river inunda-
tion in Java, 246.

Currents, distribution of drift-timber
by, 245.

Curtis, Mr., on the ravages caused by

aphides, 136.
Curtis, Mr. John^ on the power of the

tipulffi to cross the sea, 116.

on insects in marl, 245.

Cutch, effects of the earthquake of, in

1819, 265.
Cuvier on the variability in the same

species, 25.

on the varieties of the dog, 27.

■ on identity of Egyptian mummies

with living species, 30.
! on the migrations of the Spring.

bok, 95.

on the extinction of the Dodo, 151.

on the durability of the bones of

men, 258.

Cuvier, M. P., on the aptitude of some
animals to domestication, 38.

on the influence of domestication,

41.

Cypris found completely fossilized in
Scotch marl lakes, 275.

not uncommon in ponds in Eng-
land, 275.

Dangerfield, Captain P., on buried cities
in Central India, 238.

Daubeney, Dr., his discovery of nitro-
gen in mineral springs, .189.

Davy, Sir H., on the occurrence of gyp-
sum in peat, 210.

his objection to the theory of the

gradual civilization of man, 117.

on the perishable nature of the

works of man, 271.

Davy, Dr., on the changes which a
helmet taken up from the sea near
Corfu had undergone, 263.

Decandolle, his opinion respecting hy-
brid plants, 56.

on the distribution of plants, 68,71.

— — on the agency of man in the dis-
persion of plants, 82.

■ on the causes of stations of plants,

131.

on the barriers which separate dis-
tinct botanical provinces, I77.

Decandolle, M. Alph., on the number of
botanical provinces, 71.

Deer, their powers of swimming, 92.

formerly very abundant in Scot-
land, 149.

abundance of their remains in the

Scotch marl lakes, 251.
Deguer on remains of ships, &c, in the

Dutch peat mosses, 219.
Degradation of land, caused by rain

199.

De la Beche, M., on the action of rain
in the tropics, 200.

316

INDEX.

De la Beche, M., on the drifting of the
lighter parts of plants to sea by hur-
ricanes, 244.

■ • his remarks on the subsidence at

Port Royal, 269.

; on the coral formations of the West

Indian seas, 291.

on the alternation of coral and lava

in the Isle of Prance, 295.

Delametberie, speculative views of, 11.

Delille, wheat found in the Egyptian
tombs by, 31.

on the native country of the com-
mon wheat, 31.

Delta of the Ganges, alternations of ma-
rine and fresh-water strata formed in
the, 277.

of the Indus, recent elevation and

depression of the, 277-
■ of the Rhone, cannon inclosed in

calcareous rock taken up from the,

262.

De Luc on the conversion of forests into

peat mosses, 214.
Denudation caused by rain, 199.
Desert of Africa, its area as compared

to that of the Mediterranean, 166.
Desjardin, M., bones of the dodo found

fossil under lava by, 151.
Dikes numerous in the Val del Bove,

Etna, 303.
Disappointment Islands, connected with

Duff's group by coral reefs, 295.
Dislocations of strata, ancient and mo-
dern, remarks on, 195.
Distribution of species, effect of changes

in physical geography on the, 160.
effect of changes in climate on,

169.

Dodo, on the recent extinction of the,
150.

Dog, varieties of the, 26.

its distinctness from the wolf, 27-

hybrids between the wolf and, 51.

Dogs, Lamarck on the numerous races
of, 7-

1 examples of acquired instincts be-
coming hereditary in, 39.

have run wild in America, 153.

goats in Juan Fernandez destroyed

by, 154.

Domestic qualities soon developed in
some animals, but wholly denied to
others, 47.

Domestication, aptitude possessed by
some animals to, 38.

influence of, 41.

Dominica, a bed of coral found between
two lava currents in, 294.

Downham, part of the town of, over-
whelmed by blown sand, 235.

Downs, account of a cannon taken up

from the sea near the, 262.
Drift sea-weed, large banks formed by,

277-

Drift wood, a boa constrictor conveyed
to St. Vincent's on, 104.

on the imbedding of, 241.

abundant in the North Sea, 244.

conveyed in all directions by cur-
rents, 245.

Drumlanrig forest overturned by the
wind in 1756, 212.

Duff's group, these islands connected
with Diappointment islands by coral
reefs, 295.

Dulverton, pigs found entire in digging a
well at, 216.

Duncombe Park, bones of recent quadru-
peds found in a fissure in, 220.

Dureau de la Malle, M., on the changes
caused by man in different races of
dogs, 26.

— on the aptitude of some animals to

domestication, 38.
Dutch peat-mosses, remains of ships,

&c, found in, 219.
Dutch vessel found in the old channel of

the river Rother, 260.

Earth's surface, effects produced by the

powers of vitality on the, 185.
> permanent modifications produced

by the action of animal and vegetable

life on the, 209.
Earthquakes, animals most abundantly

preserved where they prevail, 230.
ravages caused by the waves of the

sea on low coasts during, 232.
in Sicily, 1693, several thousand

people entombed at once in caverns,

during, 232.
1 effects of the submersion of land

by, 264.

their effects often unheeded, 267.

their effects in imbedding cities

and forests, 268.

in the Pacific, 297-

Edrom, remains of the beaver found

in the parish of, 251.
Edwards, his account of the destruction

of the town of Savanna la Mar, 233.
Egypt, cities and towns buried under

drift sand in, 234.
Egyptian mummies identical with spe-
cies still living, 28.
Eider-ducks destroyed by a fox drifted

on ice to the island of Vidoc, 145.
Ekmark, on the diffusion of plants by

birds, 80.

Elephants, their sagacity not attributable
to their intercourse with man, 46*.

INDEX.

317

Elephants will breed in captivity, 46.

their powers of swimming, 92.

Elevation, effects which would result in

some places from partial, 1 G3.
recent, in the delta of the Indus,

266.

and subsidence, effects of alter-
nate, 307-

Elizabeth, or Henderson's Island de-
scribed — see wood-cuts No. 8 and 9,
296, 297-

Elk Island, with 700 quadrupeds, swept
away by a river-flood in Virginia, 250.

Emu in Australia will become extermi-
nated, 150.

Equilibrium among plants kept up by
insects, 132.

Eschscholtz's bay, cliffs consisting of ice
and vegetable mould in, 194.

Escrinet, Pass of, conglomerate now
forming at, 221 .

Estuaries, imbedding of fresh-water
species in, 275.

description of the manner in which

they become filled up, 270.

Etna, fourteen towns and villages co-
vered at once by the lava of, 236.

general dip of the volcanic beds of,

303.

lava currents of 1819 and 1811,

on, 304.

recent cones formed on, 304.

Extermination of species, no preroga-
tive of man, 156.

Extinction of species, successive, part of
the economy of nature, 168, 176.

Facial angle, on the gradation in in tel.
lect, as shown by the, 60.

Fei-ussac on the distribution of fresh-
water molluscs, 108.

Finland, Gulf of, its connexion with toe
White Sea, 306.

Fish, their geographical distribution,
105.

migrations of, 106.

agency of birds and water-beetles

on their distribution, 106.

Fissures, preservation of organic re-
mains in, 220, 231.

on their communication with ca-
verns, 221 .

Fleming, Dr., on the rapid flight of
birds^ 102.

his account of turtles taken on the

coast of England, 1 04.

on the changes in the animal king-
dom, caused by the increase of human
population, 148.

his account of the stranding of ce-

tacea on the British coasts, 278.

Flinders, a reef of coral 350 miles long,
described by, 2)15.

Floating islands within the tropics, ani-
mals transported by, 97-

Floods in Scotland, 1794, 248.

1829, 249.

Forests, degradation of land increased

by their destruction, 198.
rain diminished by the felling of,

200.

of America, cause of their position ,

201.

sites of many ancient ones now

covered by peat, 206, 211.
sometimes overturned by storms,

212.

in Germany destroyed by insects,

206.

submarine, remarks on their for-
mation, 268.

Forfarshire Lakes, shell marl deposits,
how formed in the, 272, 299.

chara? found fossilized in the — see

wood-cuts No. 2 and 3, 273, 274.

— — - skeletons of animals numerous in
the, 251.

Formation of coral reefs, 283.

Fort of Sindree, subsidence of, in 1819,
266.

■ — — not thrown down by the earth-
quake, 266.

Forth, effects of a storm in its estuary,
Feb. 1831, 280.

Fourcroy on the occurrence of iron in
all compact woods, 215.

Fox man-of-war, changes which some
articles, thrown up from the wreck of
the, had undergone in 33 years, 262.

France, human bones and works of art
found with extinct quadrupeds, in
the south of, 224.

number of ships of war lost during

the last war with, 256.

Franklin, on a whirlwind in Maryland,
74.

Fresh-water formations, recent, not yet
examined, in the tropics, 275.

the variety of species of testacea

but small in, 277-

Fresh-water and marine strata, alterna-
tions of, how formed in the delta of
the Ganges, 277.

Freshwater plants and animals, imbed-
ding of their remains in subaqueous
strata, 272, 275.

Fries, on the dispersion of cryptogamic
plants, 76.

Frisi, on the conservative influence of
vegetation, 198.

Frogs, conveyed to the sea in great num-
bers by floods, in Morayshire, 246.

318

INDEX,

Frontispiece described, 303.

Gaimard, M., on the depth, at which
the zoophytes, that form coral, live,
286.

Gambier Island, its windward side high-
est, 293.

Gambier's group, rate of the growth of

coral in, 287-
■ volcanic rocks found in the lagoons

of, 291.

Gamma moth, ravages caused by the ca-
terpillars of the, 136.

Ganges, islands formed by the, 203.

i bodies of men, deer, and oxen con-
veyed to the sea by the floods of the,
250.

bones of men found in the delta of

the, 258.

alternations of marine and fresh-
water strata, how formed in its delta,
277.

Gases, two of different gravities, will be-
come uniformly diffused, 188.

Genera, Linnaeus on their real exist-
ence, 19.

Geographical distribution of species, on

the laws which regulate the, 66.
Geographical distribution of plants, 67-

■ of animals, 87.

• of cetacea, 91.

Geography of plants, 67.

Geological causes divisible into two great

classes, 209.
Gerard, M., on the peat of the valley of

the Somme, 219.
Germany, forests destroyed by insects

in, 206.

Gibraltar, birds' bones found in breccia
at, 223.

■ and Ceuta, shelly strata forming

at great depths between, 281.
Gmelin on the agency of birds in the

distribution of fish, 106.
Goats, rapid multiplication of, in South

America, 153.
■ in Juan Fernandez, destroyed by

dogs, 154.

God man on the migrations of the rein-
deer, 97.

Graves, Lieut., some bulimi brought to

England by, recovered after twenty

months' abstinence, 109.
on the diffusion of insects by the

wind, 115.
Graves, Mr., on the distribution of the

bustard, 150.
Greenland, timber drifted to the shores

of, 244.

Grenada, sugar-canes destroyed by ants
in, 137.

Greville, Dr., on some remarkable accu-
mulations of drift sea-weed, 78.

Guadaloupe, human skeletons imbedded
in calcareous rock in the island of,
259.

Guilding, Rev. L., his account of the

arrival of a boa constrictor in St. Vin-
cent's, on drift wood, 104.
Giildensfadt, on the distinctness of the

clog and wolf, 28.
Gulf of Bothnia, its extent formerly

much greater, 307-
Gulf of Finland, its geological connexion

with the White Sea, 306.
Gulf-stream, great area over which

plants are drifted by the, 76, 243.
Gull-stream, account of a cannon taken

up in the, 262.
Gun-barrel, with shells attached, found

in the sands near St. Andrew's, 263.
Gypsum, Sir H. Davy on its occurrence

in peat, 210.
Gyrogonite, or petrified seed-vessel of

charse, described — see wood-cut No. 2,

273.

Habitations of plants described, 69.

Habits of animals, when acquired rarely
transmissible, 48.

Hamilton, Sir Charles, on the submerged
buildings of Port Royal, 269.

Happisborough, remarks on the so-called
submarine forest of, 268.

Harris, Hon. A., on the effects of the
foundering of a vessel off Foole har-
bour, 260.

Hatfield moss, trees of vast size found
in, 213.

Helice and Bura, submerged Grecian

towns, 269.
Helix, extensive range of some species

of, L09.

some species of very local, 109.

Helmet, changes which one taken up
from the sea near Corfu, had under-
gone, 263.

Henderson on the drifting of the polar
bear to Iceland, 143.

Henderson's Island described — see wood-
cuts No. 8 and 9, 296, 297.

Henslow, Rev. Prof., his experiments
on the cowslip, 35.

' onthediffusion of plants by birds,80.

Herbert, Hon. Mr., on some remarkable
varieties in plants, from a common
stock, 34.

■ his experiments on the cowslip, 34.

on hybrid plants, 56.

Herschell, Mr., his remarks on a change

of climate, 309.
Hilaire, M. Geof. St., on the uninter-

INDEX.

rupted succession in the animal king-
dom, 2.

Hoff, M. Von, on human remains in the
delta of the Ganges, 258.

his account of a buried vessel be-
tween Bromberg and Nakel, 260.

Hogs, rapid multiplication of, in South
America, 153.

Holland, the teredo navalis brought by-
ships to, 122.

submarine peat found in, 278.

a large cachalot stranded on the

west coast of, in 1598, 278.

Hooker, Dr., on the drifting of a fox on
ice, 145.

Horsburgh, Capt., his description of the

Maldiva Islands, 285.
on the situation of the channels

into the lagoons of coral islands, 293.
Horses, the amble hereditary in some,

44.

1 numerous, in a wild state in Mis-
sissippi valley, 152.

wild, annually drowned in great

numbers in South America, 249.

Horsfield, Dr., on the distribution of the
Mydaus meliceps in Java, 95.

Horticulture, changes in plants produced
by, 32.

Human bones, changes which some have
undergone in fourteen or fifteen cen-
turies, 225.

Human remains in peat mosses, 215.

■ in caves, 223.

their durability, 258.

found in the delta of the Ganges,

258. _ &

found in calcareous rock at Gua-

daloupe, 259.

Humboldt on the training of monkeys
to ascend trees, 47.

on the distribution of species, 67-

on the plants common to the Old

and New World, 69.

on the distribution of animals, 88.

on the periodical migrations of Ame-
rican water-fowl, 102.

on the drifting of insects by the

wind in the Andes, 114.

on the rapid multiplication of do-
mestic quadrupeds in America, 1 52.

on the comparative size of the

African desert and the Mediterra-
nean, 166.

• origin of beings said by him not to

belong to zoological geography, 179.

• his account of the annual drown-
ing of wild horses in South America,
by river floods, 249.

Humming-birds peculiar to the New
World, 100.

Humming-birds, found by Captain King

in the Straits of Magellan, in the

depth of winter, 100.

some species very local, 100.

Hunter, John, on mule animals, 50.
on the identity of the dog, wolf,

and jackal, 50.
Hunter, Mr., his account of the buried

city of Oujein, 237.
Huron, Lake, strata containing recent

shells, found on the shores of, 275.
Hurricanes, many of them connected

with submarine earthquakes, 232.
leaves of plants drifted out to sea

by, 244.

Huttonian theory, remarks on the,
196.

Hybrid races, Lamarck on the origin of,
10.

Hybrids, phenomena of, 49.

sometimes prolific, 49.

John Hunter's opinion on, 50.

not strictly intermediate between

the parent species, 51.

between the dog and wolf, 51.

among plants prolific through se-
veral generations, 52.

rare among plants in a wild state,

54.

difficulties attending their propa-
gation, 59.

Hydrangea hortensis, influence of soil
on the colour of its petals, 34.

Hydrophytes, distribution of, 72, 78.

lanthina fragilis, its extensive range,
108.

■ an active agent in disseminating

other species, 108.
Icebergs, plants transported by, 77-
Ice-floes, drifting of animals on, 97.
Iceland, the polar bear frequently drifted

from Greenland to, 143.

• rein-deer imported into, 154.

Igneous action, remarks on its intensity

at different epochs, 194.
Igneous causes, the real antagonist power

to the action of running water, 194.
Imbedding of organic remains in depo-
sits on emerged land, 209.

in peat mosses, 215.

in caves and fissures, 219.

■ in alluvium, and the ruins caused

by landslips, 228.
in volcanic formations on the land,

236.

in subaqueous deposits, 239.

by river inundations, 247.

in recent marl-lakes in Scotland,

251.

Imperieuse, coral reef, 294.

320

INDEX.

Imrie, Major, on the Gibraltar breccia,
223.

India, buried cities in Central, 237.
Indians of North America will become

exterminated, 175.
Indus, recent alterations of level in its

delta, 265, 277-
Inorganic causes, their influence in

changing the habitations of species,

158.

Insects, the fructification of plants
greatly assisted by, 54.

geographical distribution of, 112.

migrations of, 1 13.

certain types of, distinguish parti-
cular countries, 114.

■ diffused by the wind, 115.

— disseminated by animals, birds,
river-floods, &c, 116.

power of some kinds of to cross the

sea, 116.

, destructive to timber, introduced

by commerce, 122.
. parasitic, 122.

their numbers kept down by other

insects, 133.

■ peculiarity of their agency in pre-
serving an equilibrium of species, 134.

rapid propagation of some kinds of,

135.

imbedding of the remains of, 245.

only preserved under peculiar cir-
cumstances, 246.

Instincts of the bee, 58.

Instincts, migratory, occasional develop-
ment of in animals, 93.

new ones, which have become he-
reditary in some animals, 39.

modified by domestication, 44.

Ipsambul, buried temple of, 234.

Ireland, tradition of the destruction of
the reptiles of, by St. Patrick, 103.

its flora but little known, 103.

i area covered by peat in, 211.

trees of great size found in the peat

of, 212.

human body found in peat in, 215.

■ cattle lost in great numbers in the

bogs of, 217-
■ testacea found living at great

depths off the N. W. coast of, 282.
Iron, common in all compact woods,

215.

ore in peat, whence derived, 214.

instruments, account of some taken

up from the bottom of the sea, in-
cased in conglomerate, 262.

Islands, vegetation of, 70, 227-

the migration of plants aided by,

77-

animals found in, 90.

Islands of the Pacific, animals found in,
90.

coral, manner in which they are

formed, 284.
■ of drift wood, with trees growing

on them, discovered at sea, 98.
Isle of France, alternation of coral and

lava seen in the, 295.
Isthmus of Sleswick, action of the sea on

the, 165.

effects which would result from its

destruction, 165.
Italian peninsula, in great part elevated

since present marine species were in

being, 178.

J amaica, seeds drifted to Europe from,
76.

subsidence in the harbour of Port

Royal in, 161, 264.
rain diminished in, by the felling

of forests, 200.
a town in, swept away by the sea,

233.

James, Mr., on the herds of bisons in the
Mississippi Valley, 93.

Java, imbedding of the remains of rep-
tiles in, 246.

animals destroyed by river-floods

in, 250.

John de Mayen, drift wood on the

island of, 244.
Juan Fernandez, goats destroyed by

dogs in, 154.

Kamtschatka, migrations of rats in, 94.

Kangaroo is giving way before the pro-
gress of society in Australia, 150.

Keith on the dispersion of seeds by ri-
vers and torrents, 76.

King, Mr., on the number of cattle lost
in bogs in Ireland, 217.

, , his account of a cannon taken up

from the Downs, 262.

King, Capt. P., on the coral reefs of
New Holland, 285, 294.

Kinnordy, Loch of, remains of insects
found in marl in the, 245.

Kirby, Rev. Mr., on the instincts of the
bee, 58.

on the distribution of insects, 113.

on the dissemination of insects by

river-floods, 116.

on the rapid propagation of some

insects, 135.

on the devastations caused by ants

in Grenada, 137-

Knight, Mr., on the wearing out of gar-
den varieties of fruit, 33.

Kolreuter, his experiments on hybrids,
between two species of tobacco, 52.

INDEX.

Konig, Mr., on the rock in which the

human skeletons from Guadaloupe are

imbedded, 259.
Kotzebue, his account of a canoe drifted

1500 miles, 119.
■ on the formation of coral islands,

284.

Krantz on the migrations of seals, 99.

Labrador, drift timber carried to the

shores of, 244.
Laccadive Islands, their linear direction,

285.

Lacepede on identity of Egyptian mum-
mies with living species, 30.

Lagoons of coral islands, volcanic rocks
sometimes found in them, 291.

cause of the narrow opening into

the, 291.

1 the entrances into them always on

the leeward side, 293.
Lake, formed by subsidence in the delta

of the Indus, 1819, 266.
has become more salt than the sea,

267.

Lakes of North America, animals inha-
biting them would be destroyed if
they were drained, 168.

— — strata containing recent shells
formed by the, 275.

Lam an tine -cast ashore near Leith, 278.

Lamarck, his definition of the term spe-
cies, 3.

his theory of the transmutation of

species, 3,

on the origin of the cultivated

wheat, 6.

■ on the numerous races of dogs,

on the production of new organs

in animals, 7-

on the origin of hybrid races, 10.

his theory of progressive develop-
ment, 11.

his definition of Nature, 13.

■ on the conversion of the orang-
outang into the human species, 14.

— — on identity of Egyptian mummies
with living species, 30.

answer to his objection as to the

native country of wheat, 31,

on the power of species to modify

their organization, 169, 173.

•< on the abundance of polyps in the

ocean, 181.

Larr.ouroux on the distribution of hy-
drophytes, 72.

Lancashire, eight canoes found in drain-
ing a lake in, 260.

recent discovery q£ a bed of ter.
tiary shells in, 306,

To?,. |i.

Land has increased in the northern he-
misphere since the commencement of
the tertiary era, 307-

Landslips, imbedding of organic remains
in the ruins caused by, 229.

villages and their inhabitants bu-
ried by, 229.

Lapland, migrations of squirrels in, 94.

Latham on the great geographical range
of some birds, 101.

Latreille on the geographical distribu-
tion of insects, 112.

Lauder, Sir T. D., his account of pigs
swimming to great distances, 92.

his account of the number of frogs

carried down to the sea by the floods
in Morayshire, 246, 249.

on the imbedding of animals by

floods in Scotland, 230.

Lava currents, of 1819 and 1811, of
Etna, described — see Frontisjnece,
304.

Lawrence on the causes which enable
man to live in all climates, 62.

Leigh, his account of canoes found in
draining Martin Meer, 260.

Lemings of Scandinavia migrate in vast
numbers, 94.

Lesley on the former abundance of deer
in Scotland, 149.

Lesueur on the geographical distribu-
tion of fish, 105.

■ on the distribution of zoophytes,

111.

Lewes, state of some human bones found

in a tumulus near, 225.
■ estuary of the Ouse recently filled

up near, 275.
Levels, indusia found in the blue

clay of, 245.
Lichens, height at which they can grow,

75.

Lignite, wood probably converted into,
more rapidly under great pressure,
261.

Limestone, the theory that it is all of
animal origin, considered, 298.

Lindley on the dispersion of cryptogam ic
plants, 75-

Linear direction of coral islands, 286.

Linnaeus on the constancy of species, 3,

on the real existence of genera in

nature, 19.

on the distribution of seeds by ani-
mals, 79.

— — on the diffusion of plants by man,

83.

— — on the original introduction of

species, 123.
Lisbon, subsidence of the quay at, 195 }

864,

322

INDEX.

Lloyd's lists, number of vessels wrecked
between 1793 and 1829, as shown by,
257.

Loch Doon, seven canoes found in, 261.
Loch Fithie, why no marl formed in,
299.

Loch Marlie, remains of thebeaver found
in, 251.

Loch of Kinnordy, remains of insects

found in mai-l in the, 245.
Locusts, devastations caused by, 137.
a great bank formed in the sea by

their dead bodies, 138.
London basin, tertiary deposits of the,

305.

Lonch, M., on the migration of the

painted lady butterfly, 1 14.
Lowe, Mr,, on the land-mollusca of

Madeira and Porto Santo, 109.
Lybian sands, caravans overwhelmed by

the, 235.

Lyon, Capt., on the imbedding of the
carcasses of camels in the African
sands, 235.

Macculloch, Dr., on the gradation from

peat to coal, 211 .
on the occurrence of tannin in

peat, 216.

his theory that all limestone is of

animal origin considered, 298.

Mackenzie, Sir G., on the importation
of the rein-deer into Iceland, 154.

Mackenzie river, accumulation of vege-
table matter in, 241.

— — beds of wood-coal found on its
banks, 242.

cause of the abundance of drift

timber in, 243.

Maclaren on the quantity of useful soil
in America, 155.

■ ■ on the position of the American

forests, 201.

Maclure, Mr., on the alternation of coral
and lava in the West Indies, 294.

Madagascar, great extent of coral near,
285.

Majendie, M., on the faculty of the re-
triever, 40.
Malabar, a great sea of coral near, 285.
Malcolm, Sir J., on the buried cities in

central India, 238.
Maldivas, description of the chain of

coral islands called the, see Wood-cut,

No. 4, 285, 286.
Malte-Brun on the verdant rafts of the

Mississippi, 98.
■ his account of a crocodile taken in

the Rhone, 104.
on the geographical distribution of

fish, 106.

Malte-Brun on the diffusion of man,
119.

on destructive insects introduced

by commerce, 122.

on the level of the Caspian, 163.

on the destruction of villages by

landslips, 229.
— — on the burying of villages under

blown sand, 235.
1 on the abundance of drift wood in

the North Sea, 244.
on the drifting of bodies to the sea

by the Ganges, 250.
on the coral reefs of the Pacific,

295.

Mammalia, different regions of indi-
genous, 88.

Man, Lawrence on the causes which
enable him to live in all climates, 62.

his agency in the dispersion of

plants, 82.

geographical distribution and dif-
fusion of, 116.

speculations on the probable birth-
place of, 116.

his involuntary influence in dif«

fusing animals and plants, 121.

— — . changes caused by, 146.

recent origin of, 155, 270.

effects of the diffusion of, 155.

power of exterminating species no

prerogative of, 156.

his influence in modifying the

physical geography of the globe, 202.

imbedding of the remains of, and

his works, in subaqueous strata,
253.

circumstances under which his re-
mains may be preserved in recent de-
posits, 255.

perishable nature of the works of,

271.

Mantel], Mr., on the superior solidity of
human bones from a Saxon tumulus
to those in a recent skeleton, 225.

remains of insects found in Lewes

levels by, 245.

his description of the recent strata

in the valley of the Ouse, 275.

Map, explanation of the, 304.

Marine and fresh-water strata, alterna-
tions of, how formed in the delta of
the Ganges, 277-

Marine deposits, imbedding of fresh-
water species in, 275.

Marine formations contain in general
a great variety of species, 277-

Marine plants and animals, imbedding
of the remains of, 277-

Marine testacea, imbedding of the re-
mains of, 280.

INDEX.

323

Marine testacea, great depths at which
they have been found living, 281.

Marine vegetation, 71, 78.

Marl lakes of Scotland, animals imbed-
ded in the, 251.

charae found fossilized in the, 273.

Martin Meer, eight canoes found in
draining, 2G0.

Martius on the changes which man will
produce in Brazil, 148.

Maryland, account of a whirlwind in,
74.

Matilda island, its windward side high-
est, 293.

Meandrina, coral formed by the genus,
284.

Mediterranean, its area as compared to

the African desert, 166.
Melville Island, annual migrations of

animals into, 97-
Men, on the extermination of savage

tribes of, by civilized colonies, 175.
■ more than 100 swept away by a

river flood in Java, 250.
■ several hundreds swept away bv

the Nile, 253.

durability of the bones of, 258.

■ bones of, found in the delta of the

Ganges, 258.
Mendip hills, sediment deposited during

floods in the caves of the, 221.
Mermaid, coral reef, 294.
Mersey, a vessel discovered in its former

bed,' 260.

Metallic substances, changes which some
taken up from the bottom of the sea
have undergone, 262.

Mhysir, a buried city in central India,
238.

Migrations, of animals, 94.

■■ of cetacea, 99.

. of birds, 101.

• ■ of fish, 106.

of insects, 113.

Migratory powers indispensable to ani-
mals to enable them to keep their
ground, 159.

Mississippi, floating islands in the, 98.

. i imbedding of terrestrial plants in
its delta, 243.

valley, wild horses very numerous

in parts of the, 152.

Mpi Here ov erflowed by lava in 1GG9,
237.

Monkeys trained to ascend trees, 4?.

Morayshire, animals conveyed to the
sea by floods in, 249.

Morea, description of the formation
termed Ceramique in the, 233.

Moreau, Caesar, his tables of the naviga-
tion of Great Britain; 257-

Montoire, great size of the peat moss of,
211.

Mount Conto, town buried by the fall
of part of, 229.

Mount Grenier, five villages buried by
the fall of part of, 229.

Mountain chains, remarks on the theory
of their sudden elevation, 197.

Mules sometimes prolific, 49.

Murchison, Mr., on the 'recent conglo-
merate of Escrinet, 221.

on the tertiary strata of Lanca-
shire, 306.

Nakel, a vessel and two anchors dug up

near, 260.
Napier, Capt., his account of the animals

destroyed by floods in Scotland, 1794,

248.

Narwal found buried in mud on the

beach near Boston, 278.
skull of the, found in recent strata

in the valley of the Ouse, 276.
Nature, as defined by Lamarck, 13.
Necker supposed species could not be an-
nihilated, 128.
Neill, his account of whales stranded

at Alloa, &c, 278.
Nerbuddah river, its channel cut

through columnar basalt, 238.
Newfoundland, cattle often mired in the

bogs of, 216.
Newhaven, valley of the Ouse recently

filled up near, 275.
New Holland, mammiferous quadrupeds

of, 89.

its native inhabitants will become

extinct, 175.
extent of coral reefs off the coast

of, 285.

Nice, formation of breccias near, 221.
Nightingale, extraordinary range of the,
101.

Nile, cities and towns buried under

blown sand near the, 234.
several hundred men swept away

by a flood on the, 253.
Nitrogen common in mineral springs,

189.

North American lakes, animals inhabit-
ing them would be destroyed by their
drainage, 168.

strata containing recent shells

formed by the, 275.

North Cape, abundance of drift wood
thrown on, 244.

Nova Scotia, account of a vessel over-
turned by the bore or tidal wave in,
260.

Norway, on the comparatively recent
elevation of part of, 306.

324 INDEX.

Olafsen, on the abundance of drift wood
on the Coast of Siberia, 244.

Orang-Outang, Lamarck on its conver-
sion into the human species, 14.

taught to climb trees by the inha-
bitants of Borneo, 47.

Organic remains, imbedded in deposits
on emerged land, 209.

in peat, 210, 215.

in caves and fissures, 219.

in alluvium and the ruins caused

by landslips, 228.

in blown sand, 234.

■ in volcanic formations on the land,

236.

■ in subaqueous deposits, 239.

Osseous breccias, remarks on the form-
ation of, 232.

Otalieite, an habitual volcanic vent, 291.

Oujein, account of the buried city of,
237.

Ouse, its estuary recently filled up, 275.
section of the beds formed in its

estuary, 276.
Gwhyk.ee, an habitual volcanic vent, 291.
Oysters, &c, thrown alive on the beach

by a storm in the Forth, 280.

Pacific, animals found in the islands of
the, 90.

— — volcanic islands of the, 288.

■ a great theatre of volcanic action,

290.

all the islands yet examined in the,

are formed of coral or volcanic rocks,
290.

the calcareous formations of the,

probably all stratified, 294.
subsidence greater than elevation

in the, 296.
earthquakes felt from time to time

in the, 297.

recent changes of level in the, 297-

calcareous formations in the, the

most extensive now in progress, 298.
■ beds of oysters, &c, found on the

coral reefs of the, 283.

coral very abundant in the, 285.

Panama, effects which would follow the

sinking down of the isthmus of, 162.
Parasitic testacea, 287.
Paris basin, tertiary deposits of the,

305.

Paroxysmal convulsions, remarks on,
196.

Parrot tribes, their geographical distri-
bution, 100.

Parry, Capt., on the swimming of the
Polar bear, 97.

on the animals of Melville Island,

07.

Paviland cave, human skeleton found
in, 223, 226.

Peat, its formation has not always a
conservative tendency, 193.

— — on its growth and the preserva-
tion of organic and other remains in
it, 210.

abundant in hot and humid cli-
mates, 211.

area in Europe covered by, 211.

■ — ■ — site of ancient forests now occu-
pied by, 206, 214.

human remains found in, 215.

its antiseptic property, whence

derived, 216.

mosses, accounts of the bursting

of, 217.
- cattle mired in, 217-

animal remains in, 218.

submarine, 218, 278.

Penco uplifted 25 feet in 1750, 161.

Pennant on the distribution of animals,
89.

» his account of the migrations of

rats in Kamtschatka, 94.
Peron on the geographical distribution

offish, 105.
on the distribution of zoophytes,

111.

Persian Gulf, coral said to abound in
the, 285.

Peterhead, a large whale cast ashore
near, in 1682, 278.

Physical geography, effect of changes in,
on the distribution of species, 160, 308.

changes which have taken place

in, since the deposition of the older ter-
tiary strata, (see map,) 304.

— — effects of changes in, on climate,
308.

Pigs, fortuitous acquirements of some
not hereditary, 42.

instances of their swimming to

great distances, 92.

the carcasses of some found entire

at Dulverton in digging a well, 216.

Piz, fall of the mountain of, 229.

Plants, varieties in, produced by
culture, 32.

extent of variation in, 33.

influence of soil on the colour of

the petals of, 34.

' agency of the wind in the fructifi-
cation of, 55.

their geographical distribution, 67-

effect of climate, &c, on their dis-
tribution, 68.

number common to the old and

new world, 69.

distinct provinces of indigenous,

69.

INDEX.

325

Plants, in islands, 70, 127-

agency of the winds in the dis-
persion of, 73.

form of the seeds of some fresh-
water, 75-

on the dispersion of cryptogamic,

75.

agency of rivers and torrents in

the dispersion of, 76-
absence of liquid matter in the

seeds of, 77-
——- their migrations aided by islands,

77-

agency of animals in the distribu-
tion of, 78.

diffused by birds, 80.

agency of man in the dispersion of,

82.

causes which determine their sta-
tions, 131.

equilibrium among, kept up by in-
sects, 132.

• elements found in, 188.

1 which contribute to the formation

of peat, 210.

— . — imbedding of the remains of ter-
restrial in subaqueous deposits, 240.

■ drifted from the tropics to Iceland

by the gulf stream, 243.

their lighter parts drifted out to

sea by hurricanes, 244.

on the number that are now be-
coming fossilized, 245.

— — freshwater, imbedding of the re-
mains of, in subaqueous strata, 272.

marine, imbedding of the remains

of, 277.

Playfair on the formation of vegetable
soil, 188.

Pleurs, town of, and its inhabitants
buried by a landslip, 229.

Po, its delta rapidly increased by em-
bankments, 203.

Pointer, its stand probably a modifica-
tion of the instinct of a wild race, 40.

Polar bears, drifted from Greenland to
Iceland, 9?.

■ Scoresby on their numbers, 97.

— Capt. Parry on their power of
swimming, 97-

— — effects which may have followed
their first entrance into Iceland, 144.

Pomerania, several ships found entire in
the recent formations of, 260.

Pondres, human remains and extinct
animals found in a cave at, 225.

Poole harbour, effects of the foundering
of a vessel near its entrance, 259.

Population, human, of the globe, 148.

changes caused by the progress of,

148

Port Royal, subsidence of, in 1692, 264.
Port Royal, Mr. De la Beche's remarks

on the subsidence of, 269.
Sir C. Hamilton on the submerged

buildings of, 269.
Prevost, M. Constant, his division of

geological causes, 209.
on the drifting of plants by the

gulf stream, 243.
Pre-occupancy the most powerful barrier

against emigration, 167, 168.
Prichard, Dr., on the distinct origin of

the dog and wolf, 27.
— ■ — on the unequal transmissibility of

colour, &c. 52.

on hybrid races, 52.

on the facial angle, 61.

on the geographical distribution of

animals, 88.

on animals found in islands, 90.

on the distribution of the parrot

tribes, 100.
his account of Linnseus's theory of

the introduction of species, 124.
Progressive development, Lamarck's

theory of, 11.
Pursh on the phanerogamic plants of

the United States, 69.

Quadruped's, domestic, their rapid mul-
tiplication in America, 152.

<." ■ imbedding of the remains of terres-
trial, 247.

Quaggas, their migrations in South
Africa, 95.

Quoy, M., on the depth at which zoo-
phytes that form coral live, 286.

Raffles, Sir S., on the training of the

Sumatra baboon to ascend trees, 47.
Rain, remarks on the action of, 1 99.
— diminished by the destruction of

forests, 200.
Rats migrate in great numbers in

Kamtschatka, 94.
involuntarily introduced by man

into America, 121.
Ray, the green lizard found in Ireland

according to, 103.
Reaumur on the rapid propagation of

the Aphis, 135.
on the ravages of the Gamma

moth, 136.
Rein-deer, geographical range of the, 94.

migrations of the. 97.

imported into Iceland, 154.

Remains, human, and extinct animals

found in a cave at Pondres, 225.

found in Wokey Hole, 224.

Rennie, Rev. Dr., on the seeds of fresh-

water plants, 75.

3.26

INDEX.

Rennie, Rev. Dr., on the formation of
peat, 210.

i on the recent origin of some peat-
mosses, 212.

i on the destruction of European

forests by the Romans, 214.

— on the occurrence of iron-ore in
peat-mosses, 215.

— on the preservation of human
remains in peat, 215.

on sub-marine peat, 219.

Reptiles, their geographical distribution,
103.

. distinct regions of indigenous, 103.

— their powers of diffusion, 103.

■ in Ireland, legend of their destruc-
tion by St. Patrick, 103.

— — imbedding of the remains of, in
subaqueous deposits, 246.

Retriever, M. Majendie on the faculty
of the, 40.

Rhinoceroses, hundreds swept away by
a river flood in Java, 250.

Rhone, a cannon imbedded in calca-
reous rock taken up from its delta,
262.

Richardson, Dr., on the rocky mountain
sheep, 45.

on the imbedding of drift timber

in Slave Lake, 241.

— on the cause of the abundance of
drift wood in the Mackenzie, 243.

River inundations, animals imbedded by,
247, 248, 253.

Rocks, their antiquity may have no con-
nexion with the period of their eleva-
tion, 309.

Rocky mountain sheep, Dr. Richardson
on the, 45.

Rolander on the balance of power among
species, 133.

Roman coins, &c, discovered in peat, 21 3.

Rossberg, 800 people destroyed by the
slide of the, 229.

Rother, a Dutch vessel found buried in
its old channel, 260.

Roulin, M., on acquired instincts which
have become hereditary in dogs, 39.

Rousseau, alternation of coral and vol-
canic cinders at, 295.

Runn of Cutch, ship nails, &c, thrown
out of fissures in the, 267.

Running water, igneous causes the an-
tagonist power to the action of, 194.

Sand, drift, imbedding of organic re-
mains, &c. in, 234.

cities and towns in Egypt buried

under, 234.

■ carcasses of camels imbedded in,
235.

San Lorenzo, isle of, said to have been

formed by the subsidence of the pro-
montory of Callao, 265.
Santorin, gulf of, volcanic'rocks in the

lagoons of Gambier's group like those

in the, 291.
Sardinia, its flora but little known, 103.
Savanna la Mar, town of, swept away

by the sea, 233.
Scotland, peat mosses of, 213.

cattle often mired in them, 217-

animals imbedded by floods in, 248.

quadrupeds found imbedded in the

marl lakes of, 251.
shell marl obtained from some

small lakes in, 272.
charts found fossil in the marl lakes

of, 273.

but few species in the marls of, 277-

Scoresby, Capt., his experiments on the

impregnation of wood by sea-water,

240, 261.

Sea, its ravages on low coasts during
earthquakes, 232.

sometimes fresher at great depths

than at the surface, 287-

■ estimate of the amount of, con-
verted into land since the deposition
of the tertiary strata, 305.

Sea-cow cast ashore near Leith, 2?8.

Seals, their migration, 99.

Sea-weed, large banks formed by drift,
78, 277-

Sections of coral islands, see diagrams,
No. 6 and 7, 290.

Sedgwick, Professor, his theory of the
antagonist power of vegetation con-
troverted, 190.

on eras of paroxysmal convulsion,

197-

— on the preservation of organic re-
mains in fissures, 220.

Selside, great fissure in limestone at,
220.

Serres, E. R. A., on the changes in the
brain of the foetus in vertebrated ani-
mals, 62.

Serres, M. Marcel de, on the changes
which some human bones have under-
gone in fourteen or fifteen centuries,
225.

on human remains in French

caves, 224.

Sheep, great multiplication of in South
America, 153.

Shell marl, on the formation of, in the
lakes of Scotland, 272, 299.

Shells found in the calcareous marl of
the Scotch lakes, 272.

Shifts or faults, ancient and modern
compared, 195.

Ships, British, number annually wreck-
ed, 254, 257.

INDEX,

327

Ships of war, number lost during' the
French war, 256.

> several found buried in recent

strata, 219, 260.

Sibbald on a turtle taken in the Ork-
neys, 104.

■ his account of whales stranded at

Burnt island, &c, 273.

Siberia, drift timber accumulated on the
east coast of, 244.

Sicily, several thousand people entombed
at once by an earthquake in, 232.

Silliman, Professor, his account of a
vessel overturned by the bore or tidal
wave in Nova Scotia, 260.

Sindree, a new salt lake formed by sub-
sidence in the delta of the Indus near,
266.

the fort of, subsided without fall-
ing, 266.

— elevation of Ullah Bund near, 266.
Sipparah, river, its course changed,
238.

Skeleton, human, imbedded at Guada-

loupe, 259.

i found in Paviland cave, 223, 226.

Slave Lake, accumulation of drift timber

in, 241.

Sligo, bursting of a peat moss in, 218.
Sloane, Sir H., on the dispersion of

seeds by the gulf stream, 76.
Smith, Sir J., on the propagation of

plants by buds, grafts, &c, 32.
on the distribution of seeds by

birds, 80.

Smyth, Capt. W. II., on floating islands

of drift wood, 98.
■ on the drifting of birds by a gale

of wind in the Mediterranean, 102.
on the diffusion of insects by the

wind, 115.
on the average number of British

merchant vessels lost daily, 257.
on the number of men of war lost

from 1793 to 1829, 257.
found broken shells at great depths

between Gibraltar and Ceuta, 281.
Smyth, Lieutenant, his account of Hen-
derson's Island, 297.
Soil, its influence on the colours of the

petals of plants, 34.
Soils, on the formation of, 188.
Sohvay moss described, 217-
' a man and borse, in armour,

found in, 217-

account of the bursting of, 217.

Solway Frith, animals washed by river

floods into, 248.
Somme, peat-mosses in the valley of the,

219.

Sortino Vecchio, several thousand peo-

ple entombed at once in caverns at,
282.

South America, wild horses annually
drowned in great numbers in, 247.

recent changes of level in, 265.

Souvignargues, human remains found
with extinct animals in a cave at, 225.

Spallanzani on the effects of heat on the
seeds of plants, 77-

on the flight of birds, 1 02.

Species, definition of the term, 2.

Linneeus on the constancy of, 3. *

Lamarck's theory of the transmu-
tation of, 3.

— insufficiency of the arguments in
favour of the transmutation of, 18.

causes of the difficulty of discrimi-
nating, 21.

causes of variability in the same,

24.

extent of known variability in, 26.

variability of a, compared to that

of an individual, 36.

extent of change in, 37>

• inferences as to their reality in na-
ture, 64.

laws which regulate their geo-
graphical distribution, 66.

* . theories respecting their first in-
troduction, 123.

proposal of an hypothesis as to

their first introduction, 124.

effects which would result from the

introduction of single pairs of each,
126.

Brocchi on the extinction of, 128.

Rolander on the balance of power

among, 133.
reciprocal influence of aquatic and

terrestrial, 138.
their successive destruction part

of the order of nature, 141.
' effect of the extension of the range

of, 142.

power of exterminating them no

prerogative of man, 156.

■ ■ influence of inorganic causes in

changing their habitations, 158.

effect of changes in physical geo-
graphy on their distribution, 160, 308.

their successive extinction part of

the economy of nature, 168, 176.

effect of changes of climate on their

distribution, 1C9, 308.

influence of climate in causing one

to give way before another, 172.

barriers which oppose their distri-
bution, 172.

remarks on the conversion of one

into another, 174.

their local distribution, 176.

328 ini

Species, their recent origin, or antiquity,
maybe equally consistent with their
distribution, 177-

• speculations on the appearance of

new, 179.

on the time which might be re-
quired for the extinction of one mam-
miferous, 182.

Specific character, permanence of the, 18.

Spence, Mr,, on the number of instincts
of the common bee, 58.

on the distribution of insects, 113.

on the rapid propagation of some

insects, 135.

• on the devastation caused by ants

in Grenada, 137-

Spitzbergen, bays filled with drift wood
in, 244.

Spix, M., on the changes which man

will produce in Brazil, 148.
Springbok, or Cape antelope, migrates

in vast herds, 95.
Springs, mineral, in the Mediterranean,

287-

Squirrels, migrations of the common, in

Lapland, 94.
St. Andre destroyed by a landslip, 229.
St. Andrew's, a gun barrel found in the

sands near, with shells attached to it,

263.

St- Domingo, fragments of vases, &c,
found at a depth of twenty feet in,
259.

St. Katherine Docks, a vessel found

buried in excavating them, 260.
St. Patrick, tradition of the destruction

of the Irish reptiles by, 103.
St. Vincent, account of the arrival of a

Boa-constrictor on drift wood in the

island of, 104.
Stalagmite alternating with alluvium in

French caves, 222.
Stations., of plants, description of, 69.
of animals, circumstances which

constitute them are changeable, 141,
- of animals and plants, causes by

which they are determined, 130.
Staveren, isthmus burst through, 165.
Storm of Februaiy, 1831, in the estuary

of the Forth, effects of, 280.
Stratton, Mr., his account of buried

temples in Egypt, 234.
Subaqueous strata, imbedding of aquatic

species in, 272.
Subaqueous vegetation, 72, 78.
Submarine forests, remarks on the for-
mation of, 268.
Submarine peat, found in Holland, 2?8.

7 formed on the English coast, 278.

Submersion of land by earthquakes,

effects* qf the, 264,

EX.

Subsidence, effects which would result

from, in some places, 162.
of Port Royal in Jamaica, 264,

269.

of the quay at Lisbon, 264.

■ of part of the promontory of Cal-
lao, 265.

in the delta of the Indus, 266.

in Sumbawa, 269.

of the North American lakes, 275.

greater than elevation in the Pa-
cific, 296.

and elevation, effects of alternate,

307-

Subterranean action, our knowledge of
it yet in its infancy, 195.

Sumbawa, subsidence in, 269.

Superior, lake, strata containing recent
shells formed by, 275.

Sweden, shells of recent species found
at great heights in, 306.

Switzerland, towns destroyed by land-
slips in, 229.

Tannin, its occurrence in peat, 216.
Temples in Egypt buried under blown
sand, 234.

Teredo navalis, introduced into Holland

on the bottoms of ships, 122.
Terra del Spirito Santo, the island of,

an habitual volcanic vent, 291.
Terrestrial species, imbedding of the

remains of in subaqueous deposits,

239.

Tertiary strata, changes which have
taken place in physical geography
since their deposition — sec Map, 304.

Testacea, their geographical distribu-
tion, 107.

■ causes which limit the extension

of many species, 108..

great range of some species of, 108.

some kinds capable of existing

without* air or nourishment for long
periods, 100.

their powers of diffusion — see Dia-
gram, No. 1, 111.

■ but few species of in fresh-water

formations, 277«

— — burrowing, secured from the ordi-
nary action of the waves and currents,
280.

marine, depths at which they have

been found living, 281.
parasitic, 287.

Thames, a vessel found buried in the

alluvial plain of the, 260. .
Thunder-storm in Spain, devastation

caused by a, 1 99,
Tide, channels into the lagoons of coral

jglaiuls kept open by the, 39 1 ,

INDEX.

329

Tides and currents, drifting of the
remains of animals by, 252.

Tieddemann on the changes in the
brain in the foetus of vertebrated ani-
mals, 62.

Timber destroyed by insects introduced

by commerce, 122.
Tjetandoy, river, effects of a recent flood

of the, in Java, 250.
Tobacco, hybrids between two species

of, 52.

Toomer, Mr., apig trained to hunt by, 42.

Torrents in Catalonia, devastation
caused by, 199.

Torv island, testacea found living at great
depths off, 282.

Tournal, M., human teeth and frag-
ments of pottery found in a cave by,
224.

Towns destroyed by landslips, 229.
Travertin formed in Forfarshire lakes,
273.

charas found fossil in, in Scotland,

273.

cypris found fossilized in, 275.

Trimmer, Mr., his discovery of tertiary

strata in Wales, 30G.
Tropics, recent fresh-water formations

of the, not yet examined, 275.
Turtles migrate in droves, 104.
sometimes taken on the English

coast, 104.
Turton on the drifting of wolves out to

sea on ice, 97.
his account of a turtle taken in

the Severn, 1 04.

Ullah Bund elevated in 1819 in the delta

of the Indus, 266.
section which it exhibited when

cut through by the river, 267.
Ulloa on the multiplication of the ass in

Quito, 153.
on the destruction of goats in Juan

Fernandez, by dogs, 154.
Universal formations, remarks on, 196.
Universal ocean, theory of, disproved,

124.

Val d'Arno, effect of the destruction of
forests in the upper, 198.

Valley del Bove, description of the —
(see Frontispiece,) 303.

dikes numerous in the, 303.

dip of the volcanic beds in the, 303.

Valparaiso, recent alterations of level
caused by earthquakes at, 265.

Variability, cause of, in the same spe-
cies, 24.

Variation in plants produced by horti-
culture, extent of, 33.

Vol. II.

Vegetable soil, why it does not increase

on the surface, 188.
formed in part by absorption from

the atmosphere, 189.
Vegetation, centres of, discordance of

the opinions of botanists concerning,

177-

no counterpoise to the levelling

power of water, 190.
force which it exerts compared to

the action of frost, 193.

its conservative influence, 198.

— — its influence on climate, 200.
Vermont, timber imbedded by the burst-
ing of a lake in, 228.
Vernon, Mr., on organic remains found

at North-ClifF, Yorkshire, 226.
Vessel, effects of the foundering of one

off the mouth of Poole Harbour, 259.
account of one overturned by the

bore or tidal wave, in Nova Scotia,

260.

Vessels, several found buried in recent
formations, 260.

manner in which they may be-
come preserved in subaqueous strata,
261.

Vesuvius, people destroyed by volcanic

alluvions on, 236.
Vicissitudes in the distribution of land

and sea since the commencement of

the tertiary era, 305.
Vicramaditya, Rajah, cities in Central

India overwhelmed in the time of

the, 237-

Vidal, Captain, testacea found living at

great depths by, 282.
Villages and their inhabitants buried by

landslips, 229.
Ville Deux, breccia with land shells

now forming at, 220.
Virginia, account of the destruction of

Elk island by a river flood in, 250.
Vitality, effects produced on the earth's

surface by the powers of, 185.
these most extensive in subaqueous

regions, 186.
Volcanic beds of Etna, their general

dip, 304.

cones, their perfect state no proof

of their relative age, 199.

formations, imbedding of organic

and other remains in, 236.

islands of the Pacific, 288.

Von Buch, his discovery of deposits of
recent shells in Norway, 306.

Vultures, some species true cosmopo-
lites, 101.

Walker, Dr., on the overturning of
forests by wind, 212.

330

INDEX.

West Indian seas, absence of circular
coral reefs in the, 291.

West Indies, a bed of coral found be-
tween two lava currents in the, 294.

Whales often stranded on low shores by
storms, 278.

Wheat, Lamarck on the origin of the
cultivated, 6.

answer to Lamarck's objection as

to its native country^ 31.

found in the Egyptian tombs, 31.

Whirlwinds, dispersion of seeds by, 74.

White, Mr. Ch., on the regular grada-
tion in man, &c, 61.

White, Rev. Mr., on a shower of
Aphides, 114.

White Sea, its connexion with the Gulf
of Finland, 306.

Whitsunday Island, description of — see
wood-cut, No. 5, 289.

Wiegmann on hybrids between the dog
and wolf, 51.

on hybrid plants, 53.

Wilcke on the agency of birds in the
diffusion of plants, 80.

on the manner in which an equili-
brium is kept up among plants, 132.

Willdenow on the diffusion of plants by
man, 83.

on centres of vegetable creation,

177-

Wind, forests sometimes overturned by
the, 212.

Winds dispersion of seeds by the, 73.

— : — their velocity, 74.

Windward side of coral reefs, on the

cause cf the superior height of the,

294.

Wokey Hole, human remains found in,
224.

Wolf and dog distinct species, 27.

hybrids between the, 51.

Wolves frequently drifted out to sea on

floating ice, 97-

extirpated in great Britain, 149.

Wood, Mr., on the migrations of the

wild ass, 95.
Wood instantly impregnated with salt

water when sunk to a great depth,

240.

on the imbedding of drift, 241.

— — probably converted into lignite

more rapidly under great pressure,

261.

Wood-grouse extirpated in England

within fifty years, 150.
Wreck, changes which some articles

thrown up from a, had undergone in

thirty- three years, 262.
Wrecks, average number of per year,

254, 257-

manner in which they may be pre-
served in subaqueous strata, 255.

Zoological provinces, how formed, 125.
■ ■ ■ why not more blended together,
127.

Zoophytes, their geographical distribu-
tion, 111.

.i their powers of diffusion, 112.

engaged in the construction of co-
ral reefs, 284.

their operations compared to plants

which generate peat, 283.

Zostera marina, submarine peat formed
from the, 278.

END OF THE SECOND VOLUME.

LONDON !
MINTED BY WILLIAM CLOWES,
Stamford Street.

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